REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Trustees and Shareholders
of First Trust Exchange-Traded AlphaDEX Fund:

In planning and performing our audit of the financial
statements of First Trust Exchange-Traded AlphaDEX
Fund, comprising First Trust Large Cap Core AlphaDEX
Fund, First Trust Mid Cap Core AlphaDEX Fund,
First Trust Small Cap Core AlphaDEX Fund, First
Trust Large Cap Value Opportunities AlphaDEX Fund,
First Trust Large Cap Growth Opportunities AlphaDEX
Fund, First Trust Multi Cap Value AlphaDEX Fund,
First Trust Multi Cap Growth AlphaDEX Fund, First
Trust Consumer Discretionary AlphaDEX Fund, First
Trust Consumer Staples AlphaDEX Fund, First Trust
Financials AlphaDEX Fund, First Trust Energy AlphaDEX
Fund, First Trust Health Care AlphaDEX Fund, First
Trust Industrials/Producer Durables AlphaDEX Fund,
First Trust Materials AlphaDEX Fund, First Trust
Technology AlphaDEX Fund, and First Trust Utilities
AlphaDEX Fund (collectively, the Funds), as of July
31, 2007, and for the period presented, in accordance
with the standards of the Public Company Accounting
Oversight Board (United States) (PCAOB), we
considered their internal control over financial
reporting, including control activities for 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 Funds internal control over financial reporting.
Accordingly, we express no such opinion.

The management of the Funds 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. The Funds' 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. Such internal
control includes policies and procedures that
provide reasonable assurance regarding prevention
or timely detection of unauthorized acquisition,
use, or disposition of funds 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 control deficiency 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 significant
deficiency is a control deficiency, or
combination of control deficiencies,that adversely
affects the funds' ability to initiate,authorize,
record, process, or report external financial
data reliably in accordance with generally accepted
accounting principles such that there is more than
a remote likelihood that a misstatement of the funds'
annual or interim financial statements that is more
than inconsequential will not be prevented or
detected.  A material weakness is a significant
deficiency, or combination of significant
deficiencies,that results in more than
a remote likelihood thata material misstatement
of the annual or interim financial statements
will not be prevented or detected.

Our consideration of the Funds' internal control
over financial reporting was for the limited
purpose described in the first paragraph and
would not necessarily disclose all deficiencies
ininternal control that might be significant
deficiencies or material weaknesses under standards
established by the Public Company Accounting
Oversight Board (United States).  However, we noted
no deficiencies in the Funds internal control
over financial reporting and its operation,
including controls for safeguarding securities, that
we consider to be a material weakness,
as defined above, as of July 31, 2007.

This report is intended solely for the
information and use of management and the Board
of theFunds, and the Securities and Exchange
Commission and is not intended to be and
should not beused by anyone other than these
specified parties.

Deloitte & Touche LLP

Chicago, Illinois
September 14, 2007