This study was designed to examine the effects of microwave radiation exposure on Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) larvae. One to two day old larvae were exposed to microwave radiation at the powers of 70, 150, 300 and 600 W for different exposure times (1-50 s). Mortality ratio in larvae increased significantly with increasing exposure time at all powers of microwave radiation. Completele mortality was achieved at the power of 70 W and the longest exposure time (50 s) Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (MDA) in the larvae tissue were evaluated.. SOD, CAT, GPx activities decreased and MDA level increased in the microwave radiation-treated larvae tissue compared to control group at 300 and 600 W (P < 0.05). There was no significant DNA damage detectable at 70, 150 and 300 W for 50 s when compared with control group. However, 50 s of 600 W powers was showed effects on tail length and tail intensity indicating DNA damage. These results indicate that high powers of microwave radiation treatments cause some effects on the stored product pest E. kuehniella larvae.