Exhibit 31.2

Certification of Chief Financial
Officer

I, Penni F. Roll, Chief Financial Officer of
Allied Capital Corporation, certify that:



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| | 1. | I have reviewed this quarterly report on
    Form 10-Q of Allied Capital Corporation;                                                                                                                                                                                                                                                           
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| | 2. | Based on my knowledge, this report does not
    contain any untrue statement of a material fact or omit to state
    a material fact necessary to make the statements made, in light
    of the circumstances under which such statements were made, not
    misleading with respect to the period covered by this report;                      
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| | 3. | Based on my knowledge, the financial statements,
    and other financial information included in this report, fairly
    present in all material respects the financial condition,
    results of operations and cash flows of the registrant as of,
    and for, the periods presented in this report;                                         
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| | 4. | The registrants other certifying officer
    and I are responsible for establishing and maintaining
    disclosure controls and procedures (as defined in Exchange Act
    Rules 13a-15(e) and 15d-15(e))
and internal control over
financial reporting (as defined in Exchange Act Rules 13a-15(f) and
15d-15(f))
for the registrant and have:



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| | a. | designed such disclosure controls and procedures,
    or caused such disclosure controls and procedures to be designed
    under our supervision, to ensure that material information
    relating to the registrant, including its consolidated
    subsidiaries, is made known to us by others within those
    entities, particularly during the period in which this report is
    being prepared;                               
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| | b. | designed such internal control over financial reporting, or caused such internal
control over financial reporting to be designed under our supervision, 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;                                                              
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| | c. | evaluated the effectiveness of the
    registrants disclosure controls and procedures and
    presented in this report our conclusions about the effectiveness
    of the disclosure controls and procedures, as of the end of the
    period covered by this report based on such evaluation; and                                                                                                                                  
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| | d. | disclosed in this report any change in the
    registrants internal control over financial reporting that
    occurred during the period covered by the registrants most
    recent fiscal quarter (the registrants fourth fiscal
    quarter in the case of an annual report) that has materially
    affected, or is reasonably likely to materially affect, the
    registrants internal control over financial reporting; and



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| | 5. | The registrants other certifying officer
    and I have disclosed, based on our most recent evaluation of
    internal control over financial reporting, to the
    registrants auditors and the audit committee of the
    registrants board of directors (or persons performing the
    equivalent functions):



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| | a. | all significant deficiencies and material
    weaknesses in the design or operation of internal control over
    financial reporting which are reasonably likely to adversely
    affect the registrants ability to record, process,
    summarize and report financial information; and
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| | b. | any fraud, whether or not material, that involves
    management or other employees who have a significant role in the
    registrants internal control over financial reporting.                                                                                                       

Date: August 8, 2008

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|By: /s/ PENNI F. ROLL          Penni
    F. Roll
              Chief Financial Officer |  |