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           IMPORTANT REMINDER: PIONEER DIVERSIFIED HIGH INCOME TRUST
         ANNUAL MEETING OF SHAREHOLDERS ADJOURNED UNTIL OCTOBER 8, 2009

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                                 60 State Street
                           Boston, Massachusetts 02109

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                                                              September __, 2009

Dear Shareholder:

We  previously  sent you proxy  information  relating  to the annual  meeting of
shareholders  of Pioneer  Diversified  High Income Trust (HNW).  The meeting for
your fund in which you hold shares was  adjourned  for proposal 2, to approve an
Amended and Restated Management  Agreement,  until October 8, 2009 at 2:00 p.m.,
Eastern Time.



Your vote for this important meeting has not yet been received.


We encourage  you to utilize one of the  following  options today to record your
vote:



1.   Vote by Phone. You may cast your vote by phone by calling 1-800-690-6903.

2.   Vote  Through the  Internet.  You may cast your vote using the  Internet by
     logging into the Internet  address located on the enclosed proxy ballot and
     following the instructions on the website.

3.   Vote by Mail.  You may cast your vote by  signing,  dating and  mailing the
     enclosed proxy ballot in the postage paid return envelope provided.


                 Remember, your vote counts. Please vote today.

If you have any questions regarding the proposal,  please call your fund's proxy
agent, at  1-800-232-1064  Monday through Friday 9:00 a.m. to 11:00 p.m. Eastern
Time to speak with a live representative.

Your vote will help  reduce  the need for  additional  solicitation  efforts  or
additional meeting adjournments.

As the adjournment date approaches, certain shareholders may receive a telephone
call from a  representative  from the Altman  Group if your  shares have not yet
been received.

Thank you for your assistance with this important matter.