Exhibit
31.2





CERTIFICATION





I,
Francis J. Tarallo, Chief Financial Officer, certify that:





1.    
I have reviewed this report on Form 10-K of Theragenics
Corporation;





2.    
Based on my knowledge, this annual 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;





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;





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 15(d)-15(f))) for the registrant and
have:





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;





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;





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





d)    disclosed in this report any change in the
registrant's internal control over financial reporting that occurred during the
registrant's most recent fiscal quarter that has materially affected, or is
reasonably likely to materially affect, the registrant's internal control over
financial reporting.





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):





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




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.





Da te: March
13, 2008





/s/ Francis J.
Tarallo


Francis
J. Tarallo


Chief
Financial Officer