Purpose: The purpose of the present study was to determine the effect of microwave radiation 2,65mW /cm 2 on the morphology of the rat epididymidisMethods: 80 Spraque-Dawley rats were used in this study. Rats were divided two groups as unexposed control and experimental group was exposed to 2.65 mW/cm 2 for 1 hour per day. Rats were killed at days 13.0,26.0,39.0 and 52.0 respectively after irradiation or sham treatment. At the end of process, epididymidis was microscopically examined.Results: Interstitial edema, vascular congestion, slightly inflamatory cell infiltration, fibroblastic activity increasing or in some areas of the epithelium metaplasia were observed of the experimental groups.Conclusions: The frequency the symptoms mentioned here were increased depend on duration of exposure.