Sildenafil citrate is an active ingredient used successfully in the treatment of erection disorders caused by a variety of factors. The purpose of this study is to research the effects of Sildenafil citrate and vitamins A, C and E on testicular degeneration in rats with alloxan diabetes. The rats were divided into II groups; healthy control and diabetic groups. The diabetic rats were divided into X groups with ten animals in each group. Group I consisted of control diabetic rats that were given only distilled water, Group II was the diabetic group treated with glibenclarnide; Group III was the diabetic group treated with insulin, Group IV was the diabetic group treated with Sildenafil citrate, Group V was the diabetic group treated with Vitamin A, Group VI was the diabetic group treated with vitamin C, Group VII was the diabetic group treated with vitamin E, Group VIII was the diabetic group treated with Sildenafil citrate and vitamin A, Group IX was the diabetic group treated with Sildenafil citrate and vitamin C and Group X was the diabetic group treated with Sildenafil citrate and vitamin E. Testis tissue samples were collected on the 3, 7 and 15th days of treatment in control and diabetic groups. In the histopathological examination of the testicles of diabetic rats, the seminiferous tubules and interstitium of testes in the control groups were normal and the complete spermatogenic cells in the seminiferous tubules were healthy and uniformly arranged. Severe degeneration and tubular atrophy was observed in the seminiferous tubules on the 3, 7 and 15th days in the group with induced alloxan diabetes given only distilled water (Group I). The lesions on day 3rd in the diabetic group given glibenclamide (Group II) were similar to those in the diabetic control group given only distilled water. All of the tubules had been affected by the 3rd day in group three which was given insulin A small number of spermatogenic cells and giant cells were observed in some tubules. However, almost al of the degenerated tubules had healed on the 7 and 15th days. Even though, recovery on day 15th was very similar in Groups IV-X recovery was much more pronounced in. Groups VIII-X beginning from day 3rd.