BINGHAM McCUTCHEN LLP
                               ONE FEDERAL STREET
                           BOSTON, MASSACHUSETTS 02110

                                            October 31, 2013

VIA EDGAR

Securities and Exchange Commission
Division of Investment Management
100 F Street, NE
Washington, D.C. 20549

Re:  Pioneer Series Trust III (File Nos. 333-120144; 811-21664)
     Registration Statement on Form N-1A

Ladies and Gentlemen:

      This letter is to respond to comments we received from Mr. Dominic Minore
of the Staff of the Division of Investment Management of the Securities and
Exchange Commission (the "Commission") regarding Post-Effective Amendment No. 12
to the Registration Statement on Form N-1A of Pioneer Series Trust III (the
"Registrant") relating to Pioneer Disciplined Value Fund. Following are the
Staff's comments and the Registrant's responses thereto:

1. COMMENT:  The Staff asked that the Registrant provide a letter to the
             Commission that includes certain "Tandy" acknowledgments with the
             Registrant's response to the Staff's comments.

   RESPONSE: A Tandy representation letter executed in connection with the
             filing of this response is attached hereto as Exhibit A.

2. COMMENT:  The Staff requested that the Registrant confirm that the Fund does
             not intend to invest in other investment companies to the extent
             that Acquired Fund Fees and Expenses will represent 0.01% or more
             of the Fund's expenses during the next twelve months, and that
             estimated expenses related to investments in other investment
             companies are reflected in the Other Expenses line item.

   RESPONSE: The Registrant confirms that the Fund does not intend to invest in
             other investment companies to the extent that Acquired Fund Fees
             and Expenses will represent 0.01% or more of the Fund's expenses
             during the next twelve months, and that estimated expenses related
             to investments in other investment companies are reflected in the
             Other Expenses line item.

3. COMMENT:  The Staff requested that the Registrant confirm in its response
             that the adviser has no ability to recoup any amounts waived or
             expenses reimbursed under the contractual expense limitation
             arrangement discussed in Footnote 1 to the Fee Table.

   RESPONSE: The Registrant confirms that the adviser has no ability to recoup
             any amounts waived or expenses reimbursed under the contractual
             expense limitation arrangement discussed in Footnote 1 to the Fee
             Table.




4. COMMENT:  The Staff noted that the Registrant states that the contractual
             expense limitation arrangement may be terminated for a class only
             by agreement of the adviser and the Board of Trustees. The Staff
             requested that the Registrant confirm in its response that the
             Board of Trustees does not intend to terminate the arrangement
             during the next twelve months.

   RESPONSE: The Registrant confirms that it has not been informed that the
             Board of Trustees intends to terminate the contractual expense
             limitation arrangement during the next twelve months.

5. COMMENT:  The Staff requested that the Registrant confirm in its response to
             the Staff's comments that the disclosure in the prospectus
             regarding the Fund's use of derivatives addresses the observations
             and concerns noted in the letter from Barry D. Miller, Associate
             Director, Division of Investment Management, SEC to Karrie
             McMillan, General Counsel, ICI (July 30, 2010) regarding
             derivatives related disclosure by investment companies,
             particularly as such observations relate to tailored disclosure
             regarding a fund's use of derivatives. Alternatively, the Staff
             suggested that the Registrant further tailor the disclosure as to
             the specific types of derivatives the Fund intends to use in
             implementing its principal investment strategies, the approximate
             amount of the Fund's assets expected to be invested in such
             instruments and the risks applicable to such instruments.

   RESPONSE: The Registrant confirms that the disclosure in the prospectus
             regarding the Fund's use of derivatives addresses the
             considerations noted in the letter from the Division of Investment
             Management to the Investment Company Institute regarding
             derivatives-related disclosure by investment companies.

6. COMMENT:  The Staff requested that the Registrant revise the disclosure
             regarding the Fund's management fee schedule to clarify that the
             word "assets" in the description of the breakpoints in the fee
             schedule is intended to mean "average daily net assets."

   RESPONSE: The Registrant has revised the disclosure to address the
             Staff's comment.

      Please call the undersigned at (617) 951-8458 or Toby Serkin at (617)
951-8760 with any questions.

                                               Sincerely,

                                               /s/ Jeremy Kantrowitz

                                               Jeremy Kantrowitz

cc:  Terrence J. Cullen
     Christopher J. Kelley
     Roger P. Joseph
     Toby R. Serkin

                                       2




                                                                       Exhibit A

                            PIONEER SERIES TRUST III
                                 60 State Street
                           Boston, Massachusetts 02110

                                    October 31, 2013

VIA EDGAR

Securities and Exchange Commission
Division of Investment Management
100 F Street, NE
Washington, D.C. 20549

Re:   Pioneer Series Trust III (File Nos. 333-120144; 811-21664)
      Registration Statement on Form N-1A

Ladies and Gentlemen:

      In connection with the review by the Staff of the Securities and Exchange
Commission (the "Commission") of Post-Effective Amendment No. 12 to the
Registration Statement on Form N-1A for Pioneer Series Trust III relating to
Pioneer Disciplined Value Fund, filed on August 28, 2013, the Registrant
acknowledges that, with respect to filings made by the Registrant with the
Commission and reviewed by the Staff:

  (a) the Registrant is responsible for the adequacy and accuracy of the
      disclosure in the filings;

  (b) Staff comments or changes to disclosure in response to Staff comments in
      the filings reviewed by the Staff do not foreclose the Commission from
      taking any action with respect to the filings; and

  (c) the Registrant may not assert Staff comments as a defense in any
      proceeding initiated by the Commission or any person under the federal
      securities laws of the United States.

                                         Sincerely,

                                         Pioneer Series Trust III

                                           By:   /s/ Christopher J. Kelley
                                              ------------------------------
                                              Name:  Christopher J. Kelley
                                              Title: Secretary