The deterioration of male fertility, found in numerous epidemiological studies of past decades, can be connected to growing exposure to environmental toxins. Heavy metals, especially lead is widely spread and extremely toxic. The mechanism by which lead exerts toxic effects on testis is quite complex. It involves spermatogenesis, steroidogenesis, and red-ox system. The chronic lead exposure can induce functional disorder (decrease of testosterone synthesis) or morphological disorder (decrease of testicular weight and seminal vesicle, peritubular fibrosis, seminiferous tubular diameter decrease and decrease in germ cell population related to an apoptotic process). Currently existing environmental and occupational exposure to lead and increasing combined exposure to environmental toxins results in constantly increasing number of diagnosed fertility impairments.