As filed with the Securities and Exchange Commission on April 27, 2012

Registration No. 333-175035

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Amendment No. 7
to
FORM S-1
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

PetroLogistics LP
(Exact name of registrant as specified in its charter)

600 Travis Street, Suite 3250
Houston, TX 77002
(713) 255-5990
(Address, including zip code, and telephone number, including
area code, of registrant's principal executive offices)

National Corporate Research, Ltd.
615 South DuPont Highway
Dover, DE 19901
(800) 483-1140
(Name, address, including zip code, and telephone number, including
area code, of agent for service)

Approximate date of commencement of proposed sale to the public:
As soon as practicable after this Registration Statement becomes effective.

          If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box.    o

          If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

          If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

          If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

          Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer," and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

CALCULATION OF REGISTRATION FEE

(1)

Includes common units issuable upon exercise of the underwriters' option to purchase additional common units.

(2)

Estimated solely for the purpose of calculating the registration fee pursuant to Rule 457(o) of the Securities Act of 1933.

(3)

Previously paid.

          The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 13.    Other Expenses of Issuance and Distribution.

        The following table sets forth the costs and expenses to be paid by the Registrant in connection with the sale of the common units representing limited partner interests being registered hereby. All amounts are estimates except for the SEC registration fee, the Financial Industry Regulatory Authority, or FINRA, filing fee and The New York Stock Exchange listing fee.

Item 14.    Indemnification of Directors and Officers.

        The section of the prospectus entitled "The Partnership Agreement—Indemnification" is incorporated herein by reference and discloses that we will generally indemnify our executive officers and the directors and officers of our general partner and our sponsors to the fullest extent permitted by law against all losses, claims, damages or similar events. Subject to any terms, conditions or restrictions set forth in the second amended and restated partnership agreement, Section 17-108 of the Delaware Revised Uniform Limited Partnership Act empowers a Delaware limited partnership to indemnify and hold harmless any partner or other person from and against all claims and demands whatsoever.

        Section 18-108 of the Delaware Limited Liability Company Act provides that a Delaware limited liability company may indemnify and hold harmless any member or manager or other person from and against any and all claims and demands whatsoever. The limited liability company agreement of PetroLogistics GP LLC, our general partner, provides for the indemnification of its directors and officers against liabilities they incur in their capacities as such. The Registrant may enter into indemnity agreements with each of its current directors and officers to give these directors and officers additional contractual assurances regarding the scope of the indemnification set forth in the Registrant's limited liability company agreement and to provide additional procedural protections.

        The underwriting agreement that we expect to enter into with the underwriters, to be filed as Exhibit 1.1 to this registration statement, will contain indemnification and contribution provisions.

Item 15.    Recent Sales of Unregistered Securities.

        On June 9, 2011, in connection with the formation of PetroLogistics LP, or the Partnership, the Partnership issued (i) to PetroLogistics GP LLC, its general partner, the general partner interest in the Partnership and (ii) to Propylene Holdings LLC, the limited partner interest in the Partnership for $1,000. The issuance was exempt from registration under Section 4(2) of the Securities Act of 1933. There have been no other sales of unregistered securities within the past three years.

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Item 16.    Exhibits and Financial Statement Schedules.

(a)

The following exhibits are filed herewith:

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(b)

None.

Item 17.    Undertakings.

        The undersigned Registrant hereby undertakes to provide to the underwriters at the closing specified in the underwriting agreement certificates in such denominations and registered in such names as required by the underwriters to permit prompt delivery to each purchaser.

        Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the provisions described in Item 14 above, or otherwise, the Registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

        The undersigned Registrant hereby undertakes that:

(1)

For purposes of determining any liability under the Securities Act, the information omitted from the form of prospectus filed as part of this Registration Statement in reliance upon Rule 430A and contained in a form of prospectus filed by the Registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act shall be deemed to be part of this Registration Statement as of the time it was declared effective; and



(2)

For the purpose of determining any liability under the Securities Act, each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at the time shall be deemed to be the initial bona fide offering thereof.

        The Registrant undertakes to send to each limited partner at least on an annual basis a detailed statement of any transactions with PetroLogistics GP LLC, our general partner, or any of its affiliates, and of fees, commissions, compensation and other benefits paid, or accrued to, PetroLogistics GP LLC or its affiliates for the fiscal year completed, showing the amount paid or accrued to each recipient and the services performed.

        The Registrant undertakes to provide to the limited partners the financial statements required by Form 10-K for the first full fiscal year of operations of the Partnership.

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SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, the Registrant has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized in Houston. Texas, on this 27th day of April, 2012.

        Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

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QuickLinks

Item 13. Other Expenses of Issuance and Distribution.
Item 14. Indemnification of Directors and Officers.
Item 15. Recent Sales of Unregistered Securities.
Item 16. Exhibits and Financial Statement Schedules.
Item 17. Undertakings.