Background: There are evidences regarding the prevalence of dysfunction in sexual function and behavior in diabetic people. Experimental studies revealed a positive effect of withania somnifera on sexual function and behaviors. Objective: In this research, the effect of withania somnifera on sexual function in diabetic male Wistar rats was assessed by measuring the serum levels of testosterone, progesterone, estrogen, FSH and LH. Materials and Methods: Experimental diabetes mellitus type I was induced by intraperitoneal injection of a single dose (60 mg/kg) of streptozotocin (STZ) in Wistar male rats. Oral withania somnifera root was given in pelleted food at ratio of 6.25 % for 4 weeks. The levels of gonadadotropic hormones (LH, FSH), progesterone, estrogen and testosterone in animals β serum were determined after 4 weeks in all groups. Results: Withania somnifera root was effective in lowering FSH serum level in somnifera-treated animals compared to controls (p<0.05) in both diabetic and nondiabetic groups, whereas progesterone (p<0.05), testosterone (p<0.05) and LH levels (p<0.001) were significantly higher in non-diabetic treated animals. Oral somnifera root was also able to reverse the reductive effect of diabetes on the progesterone. The estrogen level did not show any significant difference in any of the groups. Conclusion: It is suggested that withania somnifera may have a regulatory effect on diabetes-induced change of the levels of gonadal-hormones, especially progesterone, in male rats. Nevertheless, somnifera is apparently only able to diminish FSH serum level in intact animals