# Exhibit 31.1

# Certification

I, M. Christine Jacobs, President and
Chief Executive Officer, certify that:

|1. |  | I have reviewed this quarterly report on Form 10-Q of Theragenics Corporation
               (the Registrant);
|-- |  | ----------------------------------------------------------------------------------------------------------------

|2. |  | Based on my knowledge, this quarterly 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 quarterly
               report;
|-- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|3. |  | Based on my knowledge, the financial statements, and other financial information
               included in this quarterly 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 quarterly 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)) for the Registrant and we have:
|-- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|a) |  | designed such disclosure controls and procedures 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 quarterly report is being prepared;
|-- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|b) |  | evaluated the effectiveness of the Registrants disclosure controls and
                    procedures as of a date within 90 days prior to the filing date of this
                    quarterly report (the Evaluation Date); and
|-- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|c) |  | presented in this quarterly report our conclusions about the effectiveness of
                    the disclosure controls and procedures based on our evaluation as of the
                    Evaluation Date;
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|5. |  | The Registrants other certifying officer and I have disclosed, based on
               our most recent evaluation, 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 in the design or operation of internal controls
                    which could adversely affect the Registrants ability to record, process,
                    summarize and report financial data and have identified for the
                    Registrants auditors any material weaknesses in internal controls; 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; and
|-- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|6. |  | The Registrants other certifying officer and I have indicated in this
               quarterly report whether or not there were significant changes in internal
               controls or in other factors that could significantly affect internal controls
               subsequent to the date of our most recent evaluation, including any corrective
               actions with regard to significant deficiencies and material weaknesses.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Date:
August 14, 2003

/s/ M. Christine
Jacobs

M. Christine JacobsChief
Executive Officer

---

# Exhibit 31.2

# Certification

I, James A. MacLennan,  Chief Financial Officer, certify that:

|1. |  | I have reviewed this quarterly report on Form 10-Q of Theragenics Corporation
               (the Registrant);
|-- |  | ----------------------------------------------------------------------------------------------------------------

|2. |  | Based on my knowledge, this quarterly 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 quarterly
               report;
|-- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|3. |  | Based on my knowledge, the financial statements, and other financial information
               included in this quarterly 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 quarterly 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)) for the Registrant and we have:
|-- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|d) |  | designed such disclosure controls and procedures 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 quarterly report is being prepared;
|-- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|e) |  | evaluated the effectiveness of the Registrants disclosure controls and
                    procedures as of a date within 90 days prior to the filing date of this
                    quarterly report (the Evaluation Date); and
|-- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|f) |  | presented in this quarterly report our conclusions about the effectiveness of
                    the disclosure controls and procedures based on our evaluation as of the
                    Evaluation Date;
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|5. |  | The Registrants other certifying officer and I have disclosed, based on
               our most recent evaluation, to the Registrants auditors and the audit
               committee of Registrants board of directors (or persons performing the
               equivalent function):
|-- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|c) |  | all significant deficiencies in the design or operation of internal controls
                    which could adversely affect the Registrants ability to record, process,
                    summarize and report financial data and have identified for the
                    Registrants auditors any material weaknesses in internal controls; and
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|d) |  | any fraud, whether or not material, that involves management or other employees
                    who have a significant role in the Registrants internal controls; and
|-- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|6. |  | The Registrants other certifying officer and I have indicated in this
               quarterly report whether or not there were significant changes in internal
               controls or in other factors that could significantly affect internal controls
               subsequent to the date of our most recent evaluation, including any corrective
               actions with regard to significant deficiencies and material weaknesses.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Date:
August 14, 2003

/s/ James A.
MacLennan

James A. MacLennanChief
Financial Officer