PURPOSE: We aimed to evaluate the effects of dehydroepiandrosterone (DHEA) on antioxidant enzyme activities, lipid peroxidation, and histopathologic changes in both testes after unilateral testicular torsion and detorsion. METHODS: Twenty-four adult male Sprague-Dawley rats were randomly divided into 4 groups (n = 6 for each group): sham operation, torsion/detorsion (T/D), T/D + vehicle, and T/D + DHEA. Three hours before detorsion, 50 mg/kg DHEA was given intraperitoneally to the T/D + DHEA group. Testicular ischemia was achieved by twisting the left testis 720 degrees clockwise for 3 hours, and reperfusion was allowed for 24 hours after detorsion. In all groups, bilateral orchiectomies to determine the testicular tissue catalase (CAT) and superoxide dismutase activities and malondialdehyde (MDA) levels and histopathologic examination were performed. RESULTS: Compared with those from the sham group, CAT activities in the ipsilateral testis obtained from the T/D group were significantly lower and MDA levels were significantly higher (P < .05 for all). Administration of DHEA prevented increases in MDA levels and decreases in CAT and superoxide dismutase activities when compared to the T/D group. Specimens from the T/D and the T/D + vehicle groups had a significantly greater histologic injury than the specimens from the sham and the T/D + DHEA groups had (P < .01 for both). CONCLUSIONS: The results suggest that DHEA may be a protective agent for preventing biochemical and histopathologic changes related to oxidative stress in testicular injury caused by testis torsion.