Exhibit
31.2
 
 **CERTIFICATION**
 
 I, James
A. MacLennan, Chief Financial Officer, certify that:
 
 1.
    I
      have reviewed this annual 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
      annual report;
 
 3.
    Based
      on my knowledge, the financial statements, and other financial information
      included in this annual 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 annual
      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 15d-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 annual 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 (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
 
 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 registrant's board of
      directors (or persons performing the equivalent
  function):
  
  
 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 controls over financial
reporting.
 Date:
March 15, 2005
 
  /s/
      James A. MacLennan
      James
      A. MacLennan
      Chief
      Financial Officer