The present study aimed to investigate the impact of gamma radiation on isoenzymes (peroxidase and polyphenyl oxidase) and DNA damage in Trogoderma granarium. The newly emerged male adults were irradiated with substerilizing and sterilizing doses of gamma radiation for the experiments (100 and 200Gy). The results showed that there was no difference in the distribution of peroxidase and polyphenyl oxidase isoenzymes, and the intensity of peroxidase isoenzymes was the same between the tested samples when compared to the control population and each other. There was a variation in the intensity of the detected polyphenyl oxidase isoenzyme. The DNA electrophoresis showed fragmentation in the gamma irradiated adults as compared to the control. Therefore, it could be concluded that these parameters could be used as a biomarker for identification of gamma irradiated T. granarium males.