This study was conducted to investigate the influence of lindane on spermatogenesis and testicular biochemical parameters and to get insight into its mechanism. Adult male albino rats were treated orally with lindane at doses of 0, 1, 2 or 4 mg/kg/day for 30 consecutive days. Testes weight and sperm count and motility were significantly decreased. Testicular activities of 3β-HSD, 17β-HSD were significantly inhibited. Testicular cholesterol level was significantly increased while glycogen and sialic acid content were significantly decreased. Testicular activities of LDH-X, γ-GT, β-glucuronidase and acid phosphatase (ACP) were significantly decreased. Aldo-ketoreductase activity was significantly decreased in response to 2 or 4 mg/kg/day of lindane while, protein carbonyl contents were significantly increased. Hydrogen peroxide and hydroxyl radical generation and LPO were significantly increased. The enzymatic antioxidants SOD, CAT and GPx and the non-enzymatic antioxidants GSH and Vit C were significantly decreased. Lindane at doses 2 and 4 mg/kg/day showed a significant reduction in Vit E, while at a dose of 1 mg/kg/day did not show any significant change. In conclusion, lindane inhibits spermatogenesis, steroidogenesis and suppresses Sertoli cell marker enzymes which may be due, partly, to oxidative stress. Lindane enhances ROS generation and LPO and depletes antioxidant enzymes and non-enzymatic antioxidants.