The book is concerned with studying the ameliorative effect salicin which was isolated from Egyptian willow leaves (Salix suberrata) against the irradiation effect on both male and female rats. It aimed to undergo comparison between responses of both male and female rats to the gamma rays at different hematological, biochemical and ultrastructural levels. This was in addition to the study at the histological levels which was carried out in the male and female reproductive organs. The study was supported by further measurements such as the oxidative stress markers and the hormonal assays which show the deleterious effect of irradiation on the reproduction process. The main objective of the study was to optimize salicin as a radioprotector against effect of gamma irradiation on the male and female reproductive organ in the hope that this molecule may be further explored as novel antioxidative radioprotector.