Pesticides like atrazine which are frequently present in everyday surroundings, have adverse impacts on human health and may contribute to male infertility. The work aimed to analyze the histological and biochemical effects of atrazine on the testis in adult albino rats and whether co-administration with resveratrol could reverse the effect of atrazine. Forty adult male albino rats in good health participated in this study. They were categorized at random into four groups: the Group Ӏ received water through a gastric tube for two months every day, the Group ӀӀ received resveratrol (20 mg/kg body weight (b.w.)) through a gastric tube for two months every day, the Group ӀӀӀ received atrazine (50 mg/kg bw) through a gastric tube for two months every day, the Group ӀV received concomitant doses of atrazine and resveratrol for two months every day. The testes of the animals were then carefully removed and prepared for biochemical, immunohistochemical, light, and electron microscopic studies. Atrazine exposure led to a significant decrease in serum testosterone hormone level, upregulation of caspase 3 and iNOS mRNA levels, destructed seminiferous tubules with few sperms in their lumens, many collagen fibres accumulation in the tunica albuginea and the interstitium, abnormal morphology of some sperms as well as many vacuolations, and damaged mitochondria in the cytoplasm of many germ cells. Concomitant administration of resveratrol can improve these adverse effects. It was concluded that atrazine exposure is toxic to the testis and impairs male fertility in adult rat and coadministration of resveratrol guards against this toxicity.