Exhibit 99.1

For Immediate Release

HARMONIC ANNOUNCES FOURTH QUARTER AND YEAR ENDED 2012 RESULTS

$75 MILLION EXPANSION OF SHARE REPURCHASE PLAN

SAN JOSE, Calif. – January 29, 2013 – Harmonic Inc. (NASDAQ: HLIT), the worldwide leader in video delivery infrastructure, announced today its preliminary and unaudited results for the fourth quarter and year ended 2012.

Net revenue for the fourth quarter of 2012 was $133.4 million, compared with $136.7 million for the third quarter of 2012 and $143.6 million for the fourth quarter of 2011. For the full year 2012, net revenue was $530.5 million, compared with $549.3 million for 2011.

The company reported GAAP net income for the fourth quarter of 2012 of $4.8 million, or $0.04 per diluted share, compared with a GAAP net loss for the third quarter of 2012 of $8.2 million, or $(0.07) per share, and GAAP net income of $4.3 million, or $0.04 per diluted share, in the fourth quarter of 2011. For the full year 2012, GAAP net loss was $10.9 million, or $(0.09) per share, compared to net income of $8.8 million, or $0.08 per diluted share, for 2011.

Non-GAAP net income for the fourth quarter of 2012 was $10.8 million, or $0.09 per diluted share, compared with $8.1 million, or $0.07 per diluted share, for the third quarter of 2012, and $14.0 million, or $0.12 per diluted share for the fourth quarter of 2011. For the full year 2012, non-GAAP net income was $29.3 million, or $0.25 per diluted share, compared with $47.5 million, or $0.41 per diluted share, for 2011. See “Use of Non-GAAP Financial Measures” and “GAAP to Non-GAAP Net Income (Loss) Reconciliation” below.

Harmonic reported GAAP gross margins of 49% and GAAP operating margins of 2% for the fourth quarter of 2012, compared to 47% and 5%, respectively, for the same period of 2011. Non-GAAP gross margins were 53% and non-GAAP operating margins were 11.0% for the fourth quarter of 2012, compared to 51% and 13%, respectively, for the same period of 2011.

As of December 31, 2012, the company had cash, cash equivalents and short-term investments of $201.2 million, an increase from $192.0 million as of September 28, 2012. In the fourth quarter, the company generated approximately $20.6 million of cash from operations and used approximately $8.3 million to repurchase 1.86 million shares of common stock under its previously announced share repurchase program.

The company also announced it will expand its existing share repurchase program by $75 million.

“During the fourth quarter we delivered our highest-ever revenue from international markets and our highest-ever gross margins, benefiting from the expansion of our global customer base and particularly strong demand for software products and follow-on licenses,” said Patrick Harshman, President and Chief Executive Officer. “This progress has been against a backdrop of slower customer spending in US cable and European markets, and reflects Harmonic’s increasingly strong competitive position and expanding market share. During the fiscal year we generated a record level of cash and initiated a stock buyback program that we are now significantly expanding.

“Looking ahead, while we do not expect an immediate reversal of macro-economic and customer investment trends, the recent CES event makes clear that new waves of investment in video infrastructure are coming. Harmonic is in the pole position to take advantage of these transformational market trends as they unfold over the next 18 months, and we will press our competitive advantage and continue to invest in new growth initiatives, including emerging market expansion, Converged Cable Access Platform, new High Efficiency Video Codec technology, and new UltraHD technology.”

Business Outlook

Harmonic anticipates net revenue in the range of $115 million to $125 million for the first quarter of 2013. GAAP gross margins and operating expenses for the first quarter of 2013 are expected to be in the range of 43% to 45% and $62 million to $63 million, respectively. Non-GAAP gross margins and operating expenses for the first quarter of 2013, which will exclude stock-based compensation and the amortization of intangibles, are anticipated to be in the range of 49% to 50% and $56 million to $57 million, respectively.

Conference Call Information

Harmonic will host a conference call to discuss its financial results at 2:00 p.m. Pacific (5:00 p.m. Eastern) on Tuesday, January 29, 2013. A listen-only broadcast of the conference call can be accessed either from the company’s website at www.harmonicinc.com or by calling +1.847. 944.7317 or +1.866.297.6395 (passcode 33961615). The replay will be available after 6:00 p.m. Pacific at the same website address or by calling +1.630.652.3042 or +1.888.843.7419 (passcode 33961615#).

About Harmonic Inc.

Harmonic (NASDAQ: HLIT) is the worldwide leader in video delivery infrastructure for emerging television and video services. The company’s production-ready innovation enables content and service providers to efficiently create, prepare, and deliver differentiated services for television and new media video platforms. More information is available at www.harmonicinc.com.

Legal Notice Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, including statements related to our expectations regarding: our final results for the fourth quarter and year ended December 31, 2012; the expansion of our stock repurchase program; our strategic emphasis on expanding our global customer base and deploying more innovative and software-rich products; our increasingly strong competitive position and market share; any immediate reversal of macro-economic and customer investment trends; new waves of investment in video infrastructure; our positioning to take advantage of transformational market trends; our continuing press of our competitive advantage; our continuing investment in new growth initiatives, respecting both geographic markets and new products; and net revenue, GAAP gross margins, GAAP operating expenses, non-GAAP gross margins and non-GAAP operating expenses for the first quarter of 2013. Our expectations regarding these matters may not materialize, and actual results in future periods are subject to risks and uncertainties that could cause actual results to differ materially from those projected. These risks include the possibility, in no particular order, that: the trends toward more high-definition, on-demand and anytime, anywhere video will not continue to develop at its current pace or will expire; the possibility that our products will not generate sales that are commensurate with our expectations or that our cost of revenue or operating expenses may exceed our expectations; the mix of products and services sold in various geographies and the effect it has on gross margins; delays or decreases in capital spending in the cable, satellite and telco and broadcast and media industries; customer concentration and consolidation; the impact of general economic conditions, including as a result of recent turmoil in the global financial markets, particularly in Europe, on our sales and operations; our ability to develop new and enhanced products in a timely manner and market acceptance of new or existing Harmonic products; losses of one or more key customers; risks associated with Harmonic’s international operations; dependence on market acceptance of several broadband services, on the adoption of new broadband technologies and on broadband industry trends; inventory management; the lack of timely availability of parts or raw materials necessary to produce our products; the impact of increases in the prices of raw materials and oil; the effect of competition, on both revenue and gross margins; difficulties associated with rapid technological changes

in Harmonic’s markets; risks associated with unpredictable sales cycles; our dependence on contract manufacturers and sole or limited source suppliers; the effect on Harmonic’s business of natural disasters; the risks that our international sales and support center will not provide the operational or tax benefits that we anticipate or that its expenses exceed our plans; and the risk that our stock repurchase program will not result in material purchases of our common stock The forward-looking statements contained in this press release are also subject to other risks and uncertainties, including those more fully described in Harmonic’s filings with the Securities and Exchange Commission, including our Annual Report on Form 10-K for the year ended December 31, 2011, our Quarterly Report on Form 10-Q for the quarter ended September 28, 2012, and our Current Reports on Form 8-K. The forward-looking statements in this press release are based on information available to the company as of the date hereof, and Harmonic disclaims any obligation to update any forward-looking statements.

Harmonic Inc.

Condensed Consolidated Balance Sheets

(Unaudited)

Harmonic Inc.

Condensed Consolidated Statements of Operations

(Unaudited)

Harmonic Inc.

Condensed Consolidated Statements of Cash Flows

(Unaudited)

Use of Non-GAAP Financial Measures

In establishing operating budgets, managing its business performance, and setting internal measurement targets, the Company excludes a number of items required by GAAP. Management believes that these accounting charges and credits, most of which are non-cash or non-recurring in nature, are not useful in managing its operations and business. Historically, the Company has also publicly presented these supplemental non-GAAP measures in order to assist the investment community to see the Company “through the eyes of management,” and thereby enhance understanding of its operating performance. The non-GAAP measures presented here are gross margin, operating expenses, net income and net income per share. The presentation of non-GAAP information is not intended to be considered in isolation or as a substitute for results prepared in accordance with GAAP, and is not necessarily comparable to non-GAAP results published by other companies. A reconciliation of the historical non-GAAP financial measures discussed in this press release to the most directly comparable historical GAAP financial measures is included with the financial statements contained in this presentation. The non-GAAP adjustments described below have historically been excluded from our GAAP financial measures. These adjustments are excess facilities and severance charges and non-cash items, such as stock-based compensation expense, amortization of intangibles, and adjustments that normalize the tax rate. With respect to our expectations under “Business Outlook” above, reconciliation of non-GAAP guidance measures to corresponding GAAP measures is not available without unreasonable efforts on a forward-looking basis due to the high variability and low visibility with respect to the charges which are excluded from these non-GAAP measures. The effects of stock-based compensation expense specific to common stock options are directly impacted by unpredictable fluctuations in our stock price. We expect the variability of the above charges to have a significant impact on our GAAP financial results.

Harmonic Inc.

Revenue Information

(Unaudited)

Harmonic Inc.

GAAP to Non-GAAP Net Income (Loss) Reconciliation

(Unaudited)

CONTACTS:

# # #