The present study was conducted to investigate the possible effect of Selenium (Sel) against Cadmium (Cd) toxicity on hormones and gonads of male rats. Male rats were divided into three groups. First group served as control, second group administrated s.c. cadmium chloride (2.5 mg kg -1) and third group injected s.c. with Sel (0.35 mg kg -1) and Cd. In the last group, the animals were treated with Sel one hour before Cd treatment. Blood samples were collected and eight animals were sacrificed after two, four, six and eight weeks. Plasma testosterone, FSH and LH were assayed using enzyme immunoassay method. The sperm quality was evaluated. Cd in the testes was determined using atomic absorption. The weights of body, testes and accessory sex organs were recorded. The treatment of the rats with Cd results in a significant decrease of testosterone, LH, sperm motility (%), body gain and weights of testes, epididymis, vas deference, seminal vesicle and prostate gland. On the other hand, the sperm abnormalities and FSH concentration increased significantly in Cd treated rats. Cd content in the testes of second group and third group increased in a time-related fashion. Cd concentration in the testes of rats treated with Cd and Sel was less than that of rats injected with Cd alone. Sel was found to reduce the deleterious effects of Cd.