BY-LAWS

                                       OF

                                  PIONEER FUND

                  (As amended and restated as of May 13, 2006)

ARTICLE I

                                   DEFINITIONS

         All capitalized terms have the respective meanings given them in the
Agreement and Declaration of Trust of Pioneer Fund, as may be amended or
restated from time to time.

ARTICLE II

                                     OFFICES

Section 1.        Principal Office.  Until changed by the Trustees, the
principal office of the Trust shall be in Boston, Massachusetts.

Section 2.        Other Offices.  The Trust may have offices in such other
places without as well as within the State of Delaware as the Trustees may from
time to time determine.

Section 3. Registered Office and Registered Agent. The Board of Trustees shall
establish a registered office in the State of Delaware and shall appoint as the
Trust's registered agent for service of process in the State of Delaware an
individual resident of the State of Delaware or a Delaware corporation or a
corporation authorized to transact business in the State of Delaware; in
each case the business office of such registered agent for service of process
shall be identical with the registered Delaware office of the Trust.

ARTICLE III

                                  SHAREHOLDERS

Section 1. Meetings. Meetings of the Shareholders of the Trust or a Series or
Class thereof shall be held as provided in the Declaration of Trust at such
place within or without the State of Delaware as the Trustee shall
designate. The holders of one-third of the Outstanding Shares of the Trust or a
Series or Class thereof present in person or by proxy and entitled to vote shall
constitute a quorum at any meeting of the Shareholders of the Trust or a Series
or Class thereof.

Section 2. Notice of Meetings. Notice of all meetings of the Shareholders,
stating the time, place and purposes of the meeting, shall be given by the
Trustees by mail or telegraphic or electronic means to each Shareholder at his
address as recorded on the register of the Trust mailed at least ten (10) days
and not more than ninety (90) days before the meeting, provided, however, that
notice of a meeting need not be given to a Shareholder to whom such notice need
not be given under the proxy rules of the Commission under the 1940 Act and the
Securities Exchange Act of 1934, as amended. Only the business stated in the
notice of the meeting shall be considered at such meeting. Any adjourned meeting
may be held adjourned without further notice. No notice need be given to any
Shareholder who shall have failed to inform the Trust of his current address or
if a written waiver of notice, executed before or after the meeting by the
Shareholder who shall have failed to inform the Trust of his current address or
if a written waiver of notice, executed before or after the meeting by the
Shareholder or his attorney thereunto authorized, is filed with the records of
the meeting.

Section 3. Record Date for Meetings and Other Purposes. For the purpose of
determining the Shareholders who are entitled to notice of and to vote at any
meeting, or to participate in any distribution, or for the purpose of any other
action, the Trustees may from time to time close the transfer books for such
period, not exceeding thirty (30) days, as the Trustees may determine; or
without closing the transfer books the Trustees may fix a date not more than
ninety (90) days prior to the date of any meeting of Shareholders or
distribution or other action as a record date for the determination of the
persons to be treated as Shareholders of record for such purposes, except for
dividend payments which shall be governed by the Declaration of Trust.

Section 4. Proxies. At any meeting of Shareholders, any holder of Shares
entitled to vote thereat may vote by proxy, provided that no proxy shall be
voted at any meeting unless it shall have been placed on file with the
Secretary, or with such other officer or agent of the Trust as the Secretary may
direct, for verification prior to the time at which such vote shall be taken. A
proxy shall be deemed signed if the Shareholder's name is placed on the proxy
(whether by manual signature, typewriting, telegraphic transmission, facsimile,
other electronic means or otherwise) by the Shareholder or the Shareholder's
attorney-in-fact. Proxies may be given by any electronic or telecommunication
device except as otherwise provided in the Declaration of Trust. Proxies may be
solicited in the name of one (1) or more Trustees or one (1) or more of the
officers of the Trust. Only Shareholders of record shall be entitled to vote. As
determined by the Trustees without the vote or consent of Shareholders, on any
matter submitted to a vote of Shareholders, either (i) each whole Share shall be
entitled to one (1) vote as to any matter on which it is entitled to vote and
each fractional Share shall be entitled to a proportionate fractional vote or
(ii) each dollar of Net Asset Value (number of Shares owned times Net Asset
Value per Share of such Series or Class, as applicable) shall be entitled to one
(1) vote on any matter on which such Shares are entitled to vote and each
fractional dollar amount shall be entitled to a proportionate fractional vote.
Without limiting their power to designate otherwise in accordance with the
preceding sentence, the Trustees have established in the Declaration of Trust
that each whole Share shall be entitled to one (1) vote as to any matter on
which it is entitled by the Declaration of Trust to vote and fractional Shares
shall be entitled to a proportionate fractional vote. When any Share is held
jointly by several persons, any one of them may vote at any meeting in person or
by proxy in respect of such Share, but if more than one (1) of them shall be
present at such meeting in person or by proxy, and such joint owners or their
proxies so present disagree as to any vote to be cast, such vote shall not be
received in respect of such Share. A proxy purporting to be executed by or on
behalf of a Shareholder shall be deemed valid unless challenged at or prior to
its exercise, and the burden of proving invalidity shall rest on the challenger.
If the holder of any such Share is a minor or a person of unsound mind, and
subject to guardianship or the legal control of any other person as regards the
charge or management of such Share, he may vote by his guardian or such other
person appointed or having such control, and such vote may be given in person or
by proxy.

Section 5. Abstentions and Broker Non-Votes. Outstanding Shares represented in
person or by proxy (including Shares which abstain or do not vote with respect
to one (1) or more of any proposals presented for Shareholder approval) will be
counted for purposes of determining whether a quorum is present at a meeting.
Abstentions will be treated as Shares that are present and entitled to vote for
purposes of determining the number of Shares that are present and entitled to
vote with respect to any particular proposal, but will not be counted as a vote
in favor of such proposal. If a broker or nominee holding Shares in "street
name" indicates on the proxy that it does not have discretionary authority to
vote as to a particular proposal, those Shares will not be considered as present
and entitled to vote with respect to such proposal.

Section 6. Inspection of Records. The records of the Trust shall be open to
inspection by Shareholders to the same extent as is permitted shareholders of a
Delaware business corporation.

Section 7. Action without Meeting. Any action which may be taken by Shareholders
may be taken without a meeting if a majority of Outstanding Shares entitled to
vote on the matter (or such larger proportion thereof as shall be required by
law) consent to the action in writing and the written consents are filed with
the records of the meetings of Shareholders. Such consents shall be treated for
all purposes as a vote taken at a meeting of Shareholders.

ARTICLE IV

                                    TRUSTEES

Section 1. Meetings of the Trustees. The Trustees may in their discretion
provide for regular or stated meetings of the Trustees. Notice of regular or
stated meetings need not be given. Meetings of the Trustees other than regular
or stated meetings shall be held whenever called by the President, the Chairman
or by any one of the Trustees, at the time being in office. Notice of the time
and place of each meeting other than regular or stated meetings shall be given
by the Secretary or an Assistant Secretary or by the officer or Trustee calling
the meeting and shall be mailed to each Trustee at least two (2) days before the
meeting, or shall be given by telephone, cable, wireless, facsimile or other
electronic mechanism to each Trustee at his business address, or personally
delivered to him at least one (1) day before the meeting. Such notice may,
however, be waived by any Trustee. Notice of a meeting need not be given to any
Trustee if a written waiver of notice, executed by him before or after the
meeting, is filed with the records of the meeting, or to any Trustee who attends
the meeting without protesting prior thereto or at its commencement the lack of
notice to him. A notice or waiver of notice need not specify the purpose of any
meeting. The Trustees may meet by means of a telephone conference circuit or
similar communications equipment by means of which all persons participating in
the meeting can hear each other at the same time and participation by such means
shall be deemed to have been held at a place designated by the Trustees at the
meeting. Participation in a telephone conference meeting shall constitute
presence in person at such meeting. Any action required or permitted to be taken
at any meeting of the Trustees may be taken by the Trustees without a meeting if
a majority of the Trustees consent to the action in writing and the written
consents are filed with the records of the Trustees' meetings. Such consents
shall be treated as a vote for all purposes.

Section 2. Quorum and Manner of Acting. A majority of the Trustees shall be
present in person at any regular or special meeting of the Trustees in order to
constitute a quorum for the transaction of business at such meeting and (except
as otherwise required by law, the Declaration of Trust or these By-laws) the act
of a majority of the Trustees present at any such meeting, at which a quorum is
present, shall be the act of the Trustees. In the absence of a quorum, a
majority of the Trustees present may adjourn the meeting from time to time until
a quorum shall be present. Notice of an adjourned meeting need not be given.

ARTICLE V

                                   COMMITTEES

Section 1. Executive and Other Committees. The Trustees by vote of a majority of
all the Trustees may elect from their own number an Executive Committee to
consist of not less than three (3) members to hold office at the pleasure of the
Trustees, which shall have the power to conduct the current and ordinary
business of the Trust while the Trustees are not in session, including the
purchase and sale of securities and the designation of securities to be
delivered upon redemption of Shares of the Trust or a Series thereof, and such
other powers of the Trustees as the Trustees may delegate to them, from time to
time, except those powers which by law, the Declaration of Trust or these
By-laws they are prohibited from delegating. The Trustees may also elect from
their own number other committees from time to time; the number composing such
committees, the powers conferred upon the same (subject to the same limitations
as with respect to the Executive Committee) and the term of membership on such
committees to be determined by the Trustees. The Trustees may designate a
chairman of any such committee. In the absence of such designation the committee
may elect its own chairman.

Section 2. Meetings Quorum and Manner of Acting. The Trustees may (1) provide
for stated meetings of any committee, (2) specify the manner of calling and
notice required for special meetings of any committee, (3) specify the number of
members of a committee required to constitute a quorum and the number of members
of a committee required to exercise specified powers delegated to such
committee, (4) authorize the making of decisions to exercise specified powers by
written assent of the requisite number of members of a committee without a
meeting, and (5) authorize the members of a committee to meet by means of a
telephone conference circuit.

         The Executive Committee shall keep regular minutes of its meetings and
records of decisions taken without a meeting and cause them to be recorded in a
book designated for that purpose and kept in the office of the Trust.

ARTICLE VI

                                    OFFICERS

Section 1. General Provisions. The officers of the Trust shall be a President, a
Treasurer and a Secretary, who shall be elected by the Trustees. The Trustees
may elect or appoint such other officers or agents as the business of the Trust
may require, including one (1) or more Vice Presidents, one (1) or more
Assistant Secretaries, one (1) or more Assistant Treasurers and a Chief
Compliance Officer. The Trustees may delegate to any officer or committee the
power to appoint any subordinate officers or agents.

Section 2. Term of Office and Qualifications. Except as otherwise provided by
law, the Declaration of Trust or these By-laws, the President, the Treasurer,
the Secretary and any other officer shall each hold office at the pleasure of
the Board of Trustees or until his successor shall have been duly elected and
qualified. The Secretary and the Treasurer may be the same person. A Vice
President and the Treasurer or a Vice President and the Secretary may be the
same person, but the offices of Vice President, Secretary and Treasurer shall
not be held by the same person. The President shall hold no other office;
however, the President may also serve as Chairman. Except as above provided, any
two (2) offices may be held by the same person. Any officer may be but none need
be a Trustee or Shareholder.

Section 3. Removal. The Trustees, at any regular or special meeting of the
Trustees, may remove any officer with or without cause, by a vote of a majority
of the Trustees then in office. Any officer or agent appointed by an officer or
committee may be removed with or without cause by such appointing officer or
committee.

Section 4. Powers and Duties of the Chairman. The Trustees may, but need not,
appoint from among their number a Chairman. When present he shall preside at the
meetings of the Shareholders and of the Trustees. He may call meetings of the
Trustees and of any committee thereof whenever he deems it necessary.

Section 5. Powers and Duties of the President. The President may call meetings
of the Trustees and of any committee thereof when he deems it necessary and
shall preside at all meetings of the Shareholders. Subject to the control of the
Trustees and to the control of any committees of the Trustees, within their
respective spheres, as provided by the Trustees, he shall at all times exercise
a general supervision and direction over the affairs of the Trust. He shall have
the power to employ attorneys and counsel for the Trust or any Series or Class
thereof and to employ such subordinate officers, agents, clerks and employees as
he may find necessary to transact the business of the Trust or any Series or
Class thereof. He shall also have the power to grant, issue, execute or sign
such powers of attorney, proxies or other documents as may be deemed advisable
or necessary in furtherance of the interests of the Trust or any Series thereof.
The President shall have such other powers and duties, as from time to time may
be conferred upon or assigned to him by the Trustees.

Section 6. Powers and Duties of Vice Presidents. In the absence or disability of
the President, the Vice President or, if there be more than one (1) Vice
President, any Vice President designated by the Trustees, shall perform all the
duties and may exercise any of the powers of the President, subject to the
control of the Trustees. Each Vice President shall perform such other duties as
may be assigned to him from time to time by the Trustees and the President.

Section 7. Powers and Duties of the Treasurer. The Treasurer shall be the
principal financial and accounting officer of the Trust. He shall deliver all
funds of the Trust or any Series or Class thereof which may come into his hands
to such Custodian as the Trustees may employ. He shall render a statement of
condition of the finances of the Trust or any Series or Class thereof to the
Trustees as often as they shall require the same and he shall in general perform
all the duties incident to the office of a Treasurer and such other duties as
from time to time may be assigned to him by the Trustees. The Treasurer shall
give a bond for the faithful discharge of his duties, if required so to do by
the Trustees, in such sum and with such surety or sureties as the Trustees shall
require.

Section 8. Powers and Duties of the Secretary. The Secretary shall keep the
minutes of all meetings of the Trustees and of the Shareholders in proper books
provided for that purpose; he shall have custody of the seal of the Trust; he
shall have charge of the Share transfer books, lists and records unless the same
are in the charge of a Transfer Agent. He shall attend to the giving and serving
of all notices by the Trust in accordance with the provisions of these By-laws
and as required by law; and subject to these By-laws, he shall in general
perform all duties incident to the office of Secretary and such other duties as
from time to time may be assigned to him by the Trustees.

Section 9. Powers and Duties of Assistant Officers. In the absence or disability
of the Treasurer, any officer designated by the Trustees shall perform all the
duties, and may exercise any of the powers, of the Treasurer. Each officer shall
perform such other duties as from time to time may be assigned to him by the
Trustees. Each officer performing the duties and exercising the powers of the
Treasurer, if any, and any Assistant Treasurer, shall give a bond for the
faithful discharge of his duties, if required so to do by the Trustees, in such
sum and with such surety or sureties as the Trustees shall require.

Section 10. Powers and Duties of Assistant Secretaries. In the absence or
disability of the Secretary, any Assistant Secretary designated by the Trustees
shall perform all the duties, and may exercise any of the powers, of the
Secretary. Each Assistant Secretary shall perform such other duties as from time
to time may be assigned to him by the Trustees.

Section 11. Chief Compliance Officer. There shall be an officer of the Trust
designated by the Trustees as the Chief Compliance Officer. The Chief Compliance
Officer shall be responsible for overseeing the compliance program maintained by
the Trust for complying with the federal securities laws and shall perform such
other duties as may be assigned to him from time to time by the Trustees or the
President.

Section 12. Compensation of Officers and Trustees and Members of the Advisory
Board. Subject to any applicable provisions of the Declaration of Trust, the
compensation of the officers and Trustees and members of an advisory board shall
be fixed from time to time by the Trustees or, in the case of officers, by any
committee or officer upon whom such power may be conferred by the Trustees. No
officer shall be prevented from receiving such compensation as such officer by
reason of the fact that he is also a Trustee.

ARTICLE VII

                                   FISCAL YEAR

         The fiscal year of the Trust shall begin on the first day of January in
each year and shall end on the last day of December in each year, provided,
however, that the Trustees may from time to time change the fiscal year. The
taxable year of each Series of the Trust shall be as determined by the Trustees
from time to time.

ARTICLE VIII

                                      SEAL

         The Trustees may adopt a seal which shall be in such form and shall
have such inscription thereon as the Trustees may from time to time prescribe.

ARTICLE IX

                        SUFFICIENCY AND WAIVERS OF NOTICE

         Whenever any notice whatever is required to be given by law, the
Declaration of Trust or these By-laws, a waiver thereof in writing, signed by
the person or persons entitled to said notice, whether before or after the time
stated therein, shall be deemed equivalent thereto. A notice shall be deemed to
have been sent by mail, telegraph, cable, wireless, facsimile or other
electronic means for the purposes of these By-laws when it has been delivered to
a representative of any company holding itself out as capable of sending notice
by such means with instructions that it be so sent.

ARTICLE X

                                   AMENDMENTS

         These By-laws, or any of them, may be altered, amended or repealed, or
new By-laws may be adopted by (a) vote of a majority of the Outstanding Shares
voting in person or by proxy at a meeting of Shareholders and entitled to vote
or (b) by the Trustees, provided, however, that no By-law may be amended,
adopted or repealed by the Trustees if such amendment, adoption or repeal
requires, pursuant to law, the Declaration of Trust or these By-laws, a vote of
the Shareholders.

                                 END OF BY-LAWS