BINGHAM McCUTCHEN LLP
                               ONE FEDERAL STREET
                          BOSTON, MASSACHUSETTS 02110

                                 March 25, 2014

VIA EDGAR
--- -----

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

Re:  Pioneer Series Trust II (File Nos. 333-110037; 811-21460)
     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. 25
to the Registration Statement on Form N-1A of Pioneer Series Trust II (the
"Registrant") relating to Pioneer Select Mid Cap Growth Fund.  Following are the
Staff's comments and the Registrant's responses thereto:

I. GENERAL COMMENT

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.
                                                                 ---------

II. COMMENTS APPLICABLE TO THE PROSPECTUS

A. FEES AND EXPENSES

1.  COMMENT:   The Staff noted that the Registrant states that the Fund may
               invest  in exchange-traded funds, and requested that the
               Registrant confirm that the Fund does not invest in exchange-
               traded funds or other investment companies to the extent that
               such investments represent 0.01% or more of the Fund's expenses
               and must be included in a separate acquired fund fees and
               expenses line item.

    RESPONSE:  The Registrant confirms that the Fund does not invest in
               exchange-traded funds or other investment companies to the extent
               that such investments represent 0.01% or more of the Fund's
               expenses and must be included in a separate acquired fund fees
               and expenses line item.




B. PRINCIPAL INVESTMENT STRATEGIES

1.  COMMENT:   The Staff requested that the Registrant update the market
               capitalization range information provided in the disclosure.

    RESPONSE:  The Registrant has updated the disclosure referenced by the
               Staff.

C. PRINCIPAL RISKS OF INVESTING IN THE FUND

1.  COMMENT:   The Staff requested that the Registrant expand the disclosure
               regarding risks of investing in REITs to elaborate further on the
               types of REITs in which the Fund may invest and any additional
               risks applicable to investing in such REITs, and to disclose that
               the expenses paid by REITs that are indirectly borne by the Fund
               are not reflected in the Fund's fee table.

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

D. PERFORMANCE

1.  COMMENT:   The Staff noted that the Fund recently participated in a
               reorganization with a series of Pioneer Series Trust I (the
               "predecessor fund"), and also that certain changes were made to
               the Fund's principal investment strategies and benchmark index in
               connection with the reorganization. The Staff suggested that the
               Registrant compare the Fund's average annual total returns to the
               returns of the benchmark indexes used by the predecessor fund and
               the Fund prior to the reorganization.

    RESPONSE:  The Registrant notes that the Fund's current benchmark index and
               the predecessor fund's benchmark index are the same. Thus, the
               Registrant compares the Fund's average annual total returns to
               the returns of the benchmark index used by the predecessor fund
               prior to the reorganization.

               However, the Registrant respectfully declines to compare the
               Fund's average annual total returns to the returns of the
               benchmark index used by the Fund prior to the reorganization.
               Prior to the reorganization, the Fund invested primarily in the
               securities of small companies and compared its returns to those
               of an index of small companies. As a result of the
               reorganization, the performance and financial history of the
               predecessor fund became the performance and financial history of
               the Fund. Unlike the Fund, the predecessor fund invested
               primarily in the securities of mid-size companies. Furthermore,
               the Fund's investment strategies changed in connection with the
               reorganization, so that, like the predecessor fund, the Fund now
               invests primarily in the securities of mid-size companies. Thus,
               the Fund's average annual total returns reflect the Fund's
               principal investment strategy to invest primarily in the
               securities of mid-size companies for all periods shown. The
               Fund's former focus on small companies is not reflected in the
               Fund's average annual total returns. Accordingly, the Registrant
               believes that it would not be useful to investors, and could be
               confusing, to compare the Fund's average annual total returns to
               the returns of the benchmark index used by the Fund prior to the
               reorganization.



E. FINANCIAL HIGHLIGHTS

1.  COMMENT:   The Staff noted that the Registrant should revise the disclosure
               to clarify that the independent registered public accounting firm
               audited the Fund's financial information for all periods shown,
               including the fiscal year ended November 30, 2013.

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

F. BACK COVER

1.  COMMENT:   The Staff requested that the Registrant revise the disclosure
               on the back cover of the prospectus to identify with greater
               specificity the documents being incorporated by reference,
               and to include sufficient information to enable the reader to
               find such documents on the Commission's EDGAR system.

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

III. STATEMENT OF ADDITIONAL INFORMATION

1.  COMMENT:   The Staff suggested that the Registrant consider adding
               disclosure to address recent events in Russia and the Ukraine.

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

2.  COMMENT:   The Staff noted that the Registrant should revise the disclosure
               with respect to the incorporation by reference of the Fund's
               financial statements to indicate that such financial statements
               were filed with the Commission on January 29, 2014.

    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




                                                                       Exhibit A
                                                                       ---------


                            PIONEER SERIES TRUST II
                                60 State Street
                          Boston, Massachusetts 02110

                                 March 25, 2014

VIA EDGAR
--- -----

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

Re:   Pioneer Series Trust II (File Nos. 333-110037; 811-21460)
      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. 25 to the
Registration Statement on Form N-1A for Pioneer Series Trust II relating to
Pioneer Select Mid Cap Growth Fund, filed on January 31, 2014, 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 II

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