This study had been conducted to evaluate the histological alternations induced by gamma irradiation in the alimentary tract of the 4th instar larvae of cowpea beetle Callosbruchus maculates (cowpea weevil). Using gamma rays at (0.25kGy, 0.50 kGy, 0.75 kGy, 1.0 and 1.5 kGy), and mortality was recorded at 48 and 96 hours after irradiation. The highest mortality 100% had been recorded at 1.5 kGy gamma irradiation, there wasn't any significance (P≥0.05) between irradiation at 1kGy and 1.5kGy but the significance was (P≤0.05) compared with other treatments. The lethal dose (LD50) of gamma irradiations at 48 and 96 hours were 0.4663 kGy and 0.4275kGy respectively; results revealed that the mortality augmented by increasing the radiation doses; indicated that the effectiveness of the application was dose-dependent. Histological variations triggered by irradiation showed obvious deformations, cytoplasmic vacuolization and apical degeneration of cells. Also, The tissues exhibited marked signs of lysis and necrosis of cells. Hence, gamma irradiation could be incorporated into the control strategy of C. maculatus as a physical control means for the reduction of loss caused by stored product insects.