The objective of the present study was to determine the pathological and genotoxic effects of atrazine (ATZ) in male Japanese quail. Adult male Japanese quail were administered ATZ daily at 0-500 mg/kg bw (A-H groups) orally for 45 days. The blood and morbid tissues were collected at day 15, 30, and 45 of the treatment. A significant decrease in feed intake, body weight, erythrocyte counts, hemoglobin and hematocrit values were observed at high ATZ dose compared to control. Leukocyte counts decreased significantly throughout the experiment in groups E-H (50-500 mg/kg bw). Grossly, testes from ATZ treated birds were comparatively smaller in size. Histologically, seminiferous tubules of testes in group H (500 mg/kg bw) exhibited decreased number of spermatocytes, necrotic nuclei of spermatids, and lesser number or absence of spermatozoa. Biliary hyperplasia and vacuolar degeneration in liver and mild renal tubular necrosis was observed in birds higher doses. Significantly longer comet tails of DNA damage in leukocytes and isolated hepatocytes were recorded with 500 mg/kg bw ATZ.