Nowadays, radiation technique is widely used food preservation and pest control. Therefore, the present study was conducted to investigate the biochemical alterations in Tribolium confusum adults irradiated with the sterilizing dose (60 Gy) or fed on flour irradiated with the sterilizing dose for flour (3Kg). The results indicated a significant decrease in the nutritional contents (protein, lipids, and carbohydrates) in the studied samples when compared to control. The digestive enzymes (protease, lipase, and amylase) of T. confusum adults were estimated and they revealed that protease and amylase activities showed a significant decline in the gamma-irradiated adults, and a significant elevation in adults feed on irradiated flour. Moreover, lipase activity was non-significantly changed in the studied samples when compared to the control. In conclusion, it is noticeable that gamma irradiation of T. confusum more effective than flour irradiation but we can use food irradiation technique in combination with other control tools for controlling T. confusum.