Shareholder Proxy Services
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                                                              September 15, 2009

                                IMPORTANT MATTER

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Re:  Pioneer Diversified High Income Trust (NYSE Amex: HNW)
     Cusip: 723653101


Dear Shareholder:

Our firm has been retained by Pioneer Diversified High Income Trust to contact
you regarding your investment in common shares of the Trust, as of record date
July 9, 2009. We have attempted to contact you, but have yet to be successful.

Please  contact us  immediately at  1-800-232-1064  between the hours of
9:00 a.m. and 11:00  p.m., Eastern Standard Time.

Thank you in advance for your assistance with this matter.


Sincerely,



Fred Bonnell
Investor Relations Supervisor
Shareholder Services
The Altman Group

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                  60 East 42nd Street, New York, New York 10165