Deterioration of male reproductive health is one of the rising problems in the recent past. Many reproductive malformations including retention of nipples, abnormal sexual behavior, birth defects, decreased spermatogenesis, reduced gonad weights and sub-fertility/ infertility have been reported in laboratory animals and wildlife exposed to endocrine disrupting chemicals. It has been reported that many pollutants act as endocrine disrupting chemicals and capable of affecting reproduction. It is also believed that, reproductive disorders are thought to originate in developing stages of the fetus s life in the womb and continue to occur throughout the reproduction. Exposure to xenobiotics during early stages of life is of particular concern since embryos are highly sensitive to toxicants. Vinclozolin is a systemic dicarboximide fungicide used to control the fungus by inhibiting the spore germination on several fruits and vegetables. We have evaluated and presented data in this book whether vinclozolin has any significant effect on reproduction in adult male rat. This book also provides valuable information on prenatal exposure to vinclozolin on changes in reproduction in adult rats.