Exhibit 99.3

ENTELLUS MEDICAL, INC.

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

The following unaudited pro forma condensed combined financial statements are based on the historical consolidated financial statements of Entellus Medical, Inc. (“Entellus”) and the historical financial statements of Spirox Inc. (“Spirox”) after giving effect to Entellus’s acquisition of Spirox (the “Acquisition”) and the assumptions and adjustments described in the accompanying notes to the unaudited pro forma condensed combined financial statements. The effective date of the Acquisition was July 13, 2017.

The unaudited pro forma condensed combined balance sheet as of March 31, 2017 is presented as if the Acquisition occurred on March 31, 2017. The unaudited pro forma condensed combined statement of operations for the three months ended March 31, 2017 and the unaudited pro forma condensed combined statement of operations for the year ended December 31, 2016 are presented as if the Acquisition had taken place on January 1, 2016. The unaudited pro forma adjustments are based upon available information and upon certain assumptions that Entellus believes are (1) directly attributable to the Acquisition, (2) factually supportable, and (3) with respect to the statement of operations, expected to have a continuing impact on the combined results.

The preliminary allocation of the purchase price used in the unaudited pro forma condensed combined financial statements is based upon preliminary estimates. The preliminary estimated fair values of certain assets and liabilities have been determined with the assistance of a third-party valuation firm and such firm’s preliminary work and are based on the actual tangible and intangible assets and liabilities that existed as of the Acquisition date. Entellus’s estimates and assumptions are subject to change during the measurement period (up to one year from the Acquisition date) as Entellus finalizes the valuations of certain tangible and intangible assets acquired and liabilities assumed in connection with the Acquisition. The primary areas of the purchase price allocation which are not yet finalized relate to identifiable intangible assets and goodwill.

The unaudited pro forma condensed combined financial statements are not intended to represent or be indicative of the results of operations or financial position of Entellus that would have been reported had the Acquisition been completed as of the dates presented, and should not be taken as representative of the future results of operations or financial position of Entellus. The unaudited pro forma condensed combined financial statements, including the notes thereto, do not reflect any potential operating efficiencies and cost savings that Entellus may achieve with respect to the combined companies. The unaudited pro forma condensed combined financial statements and notes thereto should be read in conjunction with the historical financial statements of Entellus included in the annual report on Form 10-K for the year ended December 31, 2016 filed with the Securities and Exchange Commission (SEC) on February 22, 2017, and in conjunction with the subsequent quarterly report on Form 10-Q for the fiscal quarter ended March 31, 2017 filed with the SEC on May 5, 2017, and in conjunction with the historical financial statements of Spirox included in Exhibits 99.1 and 99.2 of this Form 8-K/A.

Entellus Medical, Inc.

Unaudited Pro Forma Condensed Combined Balance Sheet

As of March 31, 2017

(in thousands)

Entellus Medical, Inc.

Unaudited Pro Forma Condensed Combined Statement of Operations

For the year ended December 31, 2016

(in thousands)

Entellus Medical, Inc.

Unaudited Pro Forma Condensed Combined Statement of Operations

For the three months ended March 31, 2017

(in thousands)

Entellus Medical, Inc.

Notes To Unaudited Pro Forma Condensed Combined Financial Statements

Note 1. Basis of Pro Forma Presentation

The unaudited pro forma condensed combined balance sheet as of March 31, 2017 and the unaudited pro forma condensed combined statements of operations for the three months ended March 31, 2017 and for the year ended December 31, 2016 are based on the consolidated historical financial statements of Entellus, a Delaware Corporation, and Spirox, a Delaware Corporation, after giving effect to Entellus’s acquisition of Spirox and the assumptions and adjustments described in the notes herein. Certain note disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States have been condensed or omitted as permitted by SEC rules and regulations.

The unaudited pro forma condensed combined financial information was prepared using the acquisition method of accounting in accordance with Accounting Standards Codification (“ASC”), Topic 805, Business Combinations (“ASC 805”), and was based on the consolidated historical financial statements of Entellus, with Entellus treated as the accounting acquirer.

The acquisition method of accounting, provided by ASC 805, uses the fair value concepts defined in ASC Topic 820, Fair Value Measurement (“ASC 820”). Under this method of accounting, the assets and liabilities of Spirox are recorded by Entellus based on their estimated fair values at the date of acquisition. Fair value is defined in ASC 820 as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” Any excess of the purchase price over the fair value of identified assets acquired and liabilities assumed will be recognized as goodwill. Many of these fair value measurements can be highly subjective and it is also possible that other professionals, applying reasonable judgment to the same facts and circumstances, could develop and support a range of alternative estimated amounts.

The preliminary allocation of the purchase price used in the unaudited pro forma condensed combined financial statements is based upon preliminary estimates. The preliminary estimated fair values of certain assets and liabilities have been determined with the assistance of a third-party valuation firm and such firm’s preliminary work. Entellus’s estimates and assumptions are subject to change during the measurement period (up to one year from the Acquisition date) as Entellus finalizes the valuations of certain tangible and intangible assets acquired and liabilities assumed in connection with the Acquisition. The primary areas of the purchase price allocation which are not yet finalized relate to identifiable intangible assets and goodwill. The actual financial position and results of operations may differ significantly from the pro forma amounts reflected herein due to a variety of factors.

The unaudited pro forma condensed combined financial statements are not intended to represent or be indicative of the results of operations or financial position of Entellus that would have been reported had the Acquisition been completed as of the dates presented, and should not be taken as representative of the future results of operations or financial position of Entellus. The unaudited pro forma condensed combined financial statements, including the notes thereto, do not reflect any potential operating efficiencies and cost savings that Entellus may achieve with respect to the combined companies.

Note 2. Spirox Acquisition

On July 6, 2017, Entellus, entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Spirox, Stinger Merger Sub, Inc., a Delaware corporation and an indirect wholly-owned subsidiary of Entellus (“Merger Sub”), and Fortis Advisors LLC, a Delaware limited liability company, solely in its capacity as representative of Spirox’s equity holders (the “Equity holders Representative”). Spirox is a privately held medical device company that develops, manufactures and markets the LATERA™ Absorbable Nasal Implant which is a minimally invasive option to treat nasal airway obstruction. On July 13, 2017, Entellus completed its acquisition of Spirox through a reverse triangular merger transaction with the terms of the Merger Agreement.

At the closing of the Acquisition, Entellus paid $25.0 million in cash and issued approximately 3.4 million shares of Entellus common stock, subject to certain adjustments and as calculated pursuant to the calculation methodology set forth in the Merger Agreement. Entellus deposited $7.5 million of the initial cash merger consideration with an escrow agent to fund payment obligations with respect to the working capital adjustment and post-closing indemnification obligations of Spirox’s former equity holders. Under the terms of the Merger Agreement, Entellus has agreed to pay additional contingent merger consideration to Spirox’s former equity holders based on Entellus’s net revenue from sales of Spirox’s LATERA™ device, subsequent versions thereof and any other device that treats nasal valve collapse or nasal lateral wall insufficiency by increasing the mechanical strength of the nasal lateral wall through the use of a synthetic graft, evaluated annually during the four-year period following the Acquisition. Entellus has the discretion to pay the contingent consideration in shares of Entellus common stock or cash, subject to compliance with applicable rules and regulations of the Securities Act of 1933, as amended (the “Securities Act”), and the NASDAQ Stock Market. A portion of the contingent consideration will be subject to certain rights of set-off for any post-closing indemnification obligations of Spirox’s equity holders. Although there is no cap on the amount of contingent consideration earn-out that could be paid, Entellus does not expect the cumulative undiscounted payments to exceed $95.0 million over the four year period. Upon completion of the acquisition accounting, including the fair value assessment of the contingent consideration, Entellus will record an estimate of the present value of contingent consideration as a liability on its balance sheet and any changes to the contingent consideration will be reflected in its Consolidated Statement of Operations.

All options and warrants to acquire shares of Spirox stock were terminated in connection with the Acquisition and the holders thereof have been entitled to receive the merger consideration that would have been payable to such holders had they exercised their vested options and warrants in full immediately prior to the effective time of the Acquisition, less the applicable exercise price of such vested options and warrants.

Entellus’s acquisition of Spirox has been accounted for as a business combination, and assets acquired and liabilities assumed were recorded at their estimated fair values as of July 13, 2017. Goodwill as of the acquisition date is measured as the excess of consideration transferred, which is also generally measured at fair value or the net acquisition date fair values of the assets acquired and the liabilities assumed. Total consideration transferred was $138.5 million and consisted of the preliminary purchase price of $80.5 million, consisting of $25.0 million cash and 3,410,292 shares of Entellus common stock (at a closing stock price on July 13, 2017 of $17.69 subject to certain discounts for the lock-up period resulting in an implied price of $16.27), and $58.0 million related to the fair value of potential additional earn-out payments based on Entellus’s net revenue from sales of Spirox’s LATERA™ device, subsequent versions thereof and any other device that treats nasal valve collapse or nasal lateral wall insufficiency by increasing the mechanical strength of the nasal lateral wall through the use of a synthetic graft, evaluated annually during the four-year period following the Acquisition. The preliminary purchase price is summarized in the table below (in thousands):

The preliminary estimated fair value of the earn-out liability was determined based on a third-party valuation. Entellus used the discounted cash flow method to measure the fair value whereby the fair value is determined based on the present value of the expected cash flows. The fair value measurement was based on significant inputs not observable in the market and thus represents a Level 3 measurement under the fair value hierarchy.

The estimated preliminary fair value of intangible assets acquired consisted of the following (in thousands):

The preliminary estimated fair value of the intangible assets acquired was determined based on a third-party valuation. Entellus used an income approach to measure the fair value of the developed technology based on the multi-period excess earnings method, whereby the fair value is estimated based upon the present value of cash flows that the applicable asset is expected to generate. Entellus used an income approach to measure the fair value of the trademarks based upon the relief from royalty method, whereby the fair value is estimated based upon discounting the royalty savings as well as any tax benefits related to ownership to a present value. Entellus used an income approach to measure the fair value of non-compete agreements and customer relationships, based on the with and without method, whereby value is estimated by discounting the cash flow differential as well as any tax benefits related to ownership to a present value. Entellus’ preliminary determination of the useful lives of these intangible assets ranges from three to twelve years. These fair value measurements were based on significant inputs not observable in the market and thus represent Level 3 measurements under the fair value hierarchy.

Inventory is measured at fair value and is determined to be a market participant’s selling price adjusted for the cost to sell and a reasonable profit allowance for the selling effort of the acquiring entity. A net deferred tax liability of $14.4 million was established as a result of the book versus tax differences attributable to the identifiable intangible assets, inventory step-up and other timing differences. This amount is also inclusive of $14.2 million of deferred tax assets related to Spirox net operating loss carry forwards. It is expected that the establishment of this net deferred tax liability in the Acquisition will result in a $14.4 million reversal of existing Entellus valuation allowance subsequent to the Acquisition. All remaining net tangible assets were valued at their respective carrying amounts, as Entellus believes that these amounts approximate their current fair values. The total purchase consideration has been allocated to the assets acquired and liabilities assumed, including identifiable intangible assets, based on their respective fair values at the acquisition date. The purchase price allocation is preliminary and subject to revision as more information becomes available but will not be revised beyond twelve months after the acquisition date. The primary areas of the purchase price allocation which are not yet finalized relate to identifiable intangible assets and goodwill. Based upon a preliminary valuation, the total preliminary purchase price was allocated as follows (in thousands):

Acquisition-related expenses incurred, including legal and accounting fees and other external costs directly related to the Acquisition, were expensed as incurred.    

Note 3. Credit Agreement

On July 13, 2017, in connection with the closing of the Acquisition, Entellus borrowed an additional $26.5 million in term loans under that certain Loan and Security Agreement dated as of March 31, 2017 among Oxford Finance LLC, the lenders listed therein, and Entellus, as amended (the “Loan Agreement”), to fund the initial cash merger consideration, bringing its total term loan borrowings under the Loan Agreement to $40.0 million. Under the Loan Agreement, Entellus was permitted to borrow up to a total of $40.0 million in term loans in three tranches (each a “Term Loan” or, collectively, “Term Loans”) and up to $10.0 million under a revolving line of credit, subject to a borrowing base requirement (the “Line of Credit”). The Term Loans under the Loan Agreement mature and all amounts borrowed under the Loan Agreement, including the Line of Credit, become due and payable on March 1, 2022.

Note 4. Pro Forma Adjustments

The following pro forma adjustments are included in the unaudited pro forma condensed combined financial statements: