The aim of this study was to investigate the protective effect of ibuprofen on testicular torsion/detorsion induced ischemia/reperfusion (I/R) injury. A total of 48 prepubertal male Wistar albino rats were divided into two models: early and late orchiectomy. Testicular torsion was created by rotating the right testis 720 degrees in a clockwise direction. The ischemia period was 5 It and orchiectomy was performed after 5 h of detorsion in the early orchiectomy model (EOM). In the late orchiectomy model (LOM), the ischemia period was 5 It and orchiectomy was performed after 7 days of detorsion. In the EOM, ibuprofen (70 mg/kg, po) was administrated only once, 40 min prior to detorsion. In the LOM, ibuprofen (70 mg/kg, po) was administered 40 min before detorsion, once daily for 7 days. Bilateral orchiectomy was performed in all groups to measure the tissue levels of malondialdehyde (MDA) and to microscopically investigate, light and electrons. The presence of endothelial nitric oxide synthase (eNOS) activity was shown with immunohistochemical studies. Spermatogenesis and mean seminiferous tubule diameter (MSTD) were significantly decreased in ipsilateral and contralateral testis when both early band late I/R groups were compared to the sham groups. Furthermore, ibuprofentreated animals showed an improved histological appearance in both models of testicular torsion. lbuprofen treatment prevented lipid peroxidation resulting in decreased MDA accumulation in the testes of both models. After I/R, eNOS immunoreactivity was increased in the testicular tissues. lbuprofen treatment decreased eNOS immunoreactivity in the germ cells of the tubules in the contralateral testes, but intense eNOS immunoreactivity was shown in the ipsilateral testes of the LOM. Electron microscopy of the testes of rats demonstrated that ibuprofen pretreatment was particularly effective in preventing the mitochondrial degeneration in both Sertoli and spermatid cells in the LOM. Because of its anti -inflammatory and antioxidant effects, ibuprofen pretreatment may have protective effects in the experimental testicular torsion/detorsion model in rats.