AimsMale infertility prevalence is higher in diabetic patients. Those patients exhibit testicular oxidative damage due to sustained hyperglycemia and inflammation. The study has investigated the efficacy of cilostazol, a phosphodiesterase 3 inhibitor, on testicular damage of diabetic rats. Main methodsStreptozotocin-induced diabetes in rats was used as a model. Six control male rats and 24 diabetic male rats were divided into the following: diabetic, cilostazol at low dose, cilostazol at high dose, and sildenafil treated rat groups. Treatment period was 4 weeks. Then, serum testosterone, testicular oxidative parameters, and testicular oxidant defenses were assayed. Real time PCR was done for quantification of Phosphoinositide 3-kinase (PI3K), Akt, and nuclear factor (NF)-κB mRNA. Expression of testicular inducible nitric oxide synthase (iNOS) was assessed. Key findingsDiabetes negatively affected the testicular tissue as evident by biochemical analysis and histopathology. Four weeks of cilostazol or sildenafil treatment improved anti-oxidative capacity, ameliorated lipid peroxidation and the pro-inflammatory iNOS expression in testicular tissue. Testosterone level and the spermatogenesis showed marked improvement. Quantitative mRNA expression showed an elevation in PI3K and Akt by cilostazol with decreasing in NF-κB level by both drugs. SignificanceOur findings suggest the beneficial role of cilostazol and sildenafil in diabetic testicular damage dependent on anti-inflammatory and anti-oxidant effects.