The present study aimed to investigate effects of rutin on diabetic-induced impairments of sexual behaviour, spermatogenesis and oxidative testicular damage. Diabetes was induced by a single injection of STZ (65 mg/kg) in male adult Wistar rats. Two weeks later, rutin (50 and 100 mg kg day ) was treated to normal and diabetic rats for 5 weeks. Sexual behaviour of the animals was observed by taking stimulus females. At the end of the study, sperm count, motility and viability were recorded. Serum levels of glucose, inflammatory markers and testosterone were also estimated. In penile tissue, cGMP levels were measured, while lipid peroxidation and antioxidant molecules and enzyme activities were determined. Finally, histopathological changes were evaluated in a cross-section of testis. Diabetic-induced alterations in male sexual behaviour and sperm count, motility and viability were markedly corrected following 5 weeks of rutin treatment to the diabetic animals. Rutin also attenuated the inhibited serum testosterone and penile cGMP content, while improved diabetic-associated inflammation and testicular lipid peroxidation and oxidative stress. Histopathological evaluation revealed damaged testicular tissues in diabetic rats, which was protected following rutin treatment. In conclusion, treatment with rutin improved sexual functionality and also protects against diabetic-induced testicular damage.