PURPOSE: This study aimed to determine the effect of melatonin in preventing ischemia-reperfusion (I-R) injury-induced tissue damage and on spermatogenesis after experimental testicular torsion (TT). METHODS: Forty peripubertal rats were divided into 4 groups each containing 10 rats: control (C), sham (S), torsion plus detorsion (TD), and torsion plus melatonin (M). The left testes were rotated 720 degrees for 6 hours and detorsed for 6 hours thereafter. Serum inhibin B (IB) levels were measured in blood samples taken from all groups. Left orchiectomies were performed to determine the tissue levels of Johnsen's scores (JS) and malondialdehyde (MDA). RESULTS: Serum IB levels in the S and TD groups were significantly lower compared with that in the C group, whereas they were higher in the M group compared with the TD group. The MDA levels were significantly lower in the C, S, and, M groups compared with the TD group. Johnsen's scores were significantly higher in the C, S, and M groups compared with the TD group. CONCLUSIONS: Our results suggested that melatonin is a potent antioxidant agent in preventing testicular I-R injury, as shown by increased IB levels and JS.