The present study was aimed to study the effect of watercress supplementation at three different levels for 8 weeks on alleviating the side effects of reused oil on sex hormones of adult male rats. Thirty male albino rats were divided into 5 groups; group (1) was fed on basal diet (as a control negative group). Group (2) was fed on basal diet containing 4 % of re-used oil substituted with oil content of the basal diet (as a control positive group). Groups (3, 4 and 5) as the same of group (2) and supplemented with 5, 7.5 and 10% dried watercress respectively.