Over the past 50 years, there has been a sharp increase in the incidence of testicular cancer and certain disorders of the male reproductive system, as well as a decline in male fertility. Despite extensive research on environmental risk factors for testicular cancer, a review of the literature does not allow for strong and consistent conclusions in this area. The hypothesis of testicular dysgenesis syndrome (TDS), based on the consequence of a disruption in gonadal development during fetal life, does not fully explain the increase in reproductive system disorders and the decline in sperm quality. The risk factors for these conditions appear to be multifactorial, involving both environmental and genetic factors. Monitoring men’s reproductive health would make it possible to eliminate the main causes affecting the male reproductive system and to identify the true environmental and genetic risk factors. (R.A.)