Report of Independent Registered Public
Accounting Firm

To the Shareowners and
Board of Trustees of Pioneer Mid Cap Value Fund
In planning and performing our audit of the financial
statements of Pioneer Mid Cap Value Fund (the
Company) as of and for the year ended October 31,
2009 in accordance with the standards of the Public
Company Accounting Oversight Board (United
States), we considered the Company's internal
control over financial reporting, including controls
over safeguarding securities, as a basis for designing
our auditing procedures for the purpose of
expressing our opinion on the financial statements
and to comply with the requirements of Form N-SAR,
but not for the purpose of expressing an opinion on
the effectiveness of the Company's internal control
over financial reporting. Accordingly, we express no
such opinion.
The management of the Company is responsible for
establishing and maintaining effective internal control
over financial reporting. In fulfilling this responsibility,
estimates and judgments by management are
required to assess the expected benefits and related
costs of controls. A company's internal control over
financial reporting is a process designed to provide
reasonable assurance regarding the reliability of
financial reporting and the preparation of financial
statements for external purposes in accordance with
generally accepted accounting principles. A
company's internal control over financial reporting
includes those policies and procedures that (1)
pertain to the maintenance of records that, in
reasonable detail, accurately and fairly reflect the
transactions and dispositions of the assets of the
company; (2) provide reasonable assurance that
transactions are recorded as necessary to permit
preparation of financial statements in accordance
with generally accepted accounting principles, and
that receipts and expenditures of the company are
being made only in accordance with authorizations of
management and directors of the company; and (3)
provide reasonable assurance regarding prevention
or timely detection of unauthorized acquisition, use or
disposition of a company's assets that could have a
material effect on the financial statements.
Because of its inherent limitations, internal control
over financial reporting may not prevent or detect
misstatements. Also, projections of any evaluation of
effectiveness to future periods are subject to the risk
that controls may become inadequate because of
changes in conditions, or that the degree of
compliance with the policies or procedures may
deteriorate.
A deficiency in internal control over financial reporting
exists when the design or operation of a control does
not allow management or employees, in the normal
course of performing their assigned functions, to
prevent or detect misstatements on a timely basis. A
material weakness is a deficiency, or a combination
of deficiencies, in internal control over financial
reporting, such that there is a reasonable possibility
that a material misstatement of the company's annual
or interim financial statements will not be prevented
or detected on a timely basis.
Our consideration of the Company internal control
over financial reporting was for the limited purpose
described in the first paragraph and would not
necessarily disclose all deficiencies in internal control
that might be material weaknesses under standards
established by the Public Company Accounting
Oversight Board (United States). However, we noted
no deficiencies in the Company's internal control over
financial reporting and its operation, including
controls over safeguarding securities, that we
consider to be a material weakness as defined above
as of October 31, 2009.
This report is intended solely for the information and
use of management and the Board of Trustees of
Pioneer Mid Cap Value Fund and the Securities and
Exchange Commission and is not intended to be and
should not be used by anyone other than these
specified parties.



Ernst & Young LLP

Boston, Massachusetts
December 19, 2009