Organic hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide have been implicated to cause oxidative stress leading to damage in membrane lipids, proteins, carbohydrates and DNA. This study was aimed to develop an in vivo animal model. The effects of hydroperoxides on testicular tissue and epididymal sperm were investigated. Male Wistar rats aged 10 - 12 weeks were randomly placed in groups and received standard rat chow and water ad libitum. Animals were injected intraperitoneally with saline (0.5 ml), t-butyl hydroperoxide (5, 10, 20 and 40 ìM; 0.5 ml) or cumene hydroperoxide cHP (2.5, 5, 10 and 20 ìM; 0.5 ml) over a 60 day period. It was found that cumenehydroperoxide cHP (10 and 20 ìM) and t-butyl hydroperoxide tbHP (20 and 40 ìM) led to significantly lower epididymal sperm concentrations and motility. Superoxide dismutase and glutathione activities were also higher with an accompanying increase in lipid peroxidation in both testicular tissue and epididymal sperm. It can be concluded that in vivo intraperitoneal administration of organic hydroperoxides negatively affect the male reproductive system. We have therefore successfully createdan animal model to test the adverse effects of oxidative stress on male reproductive parameters, thereby, enabling us to study possible in vivo treatments.