Administration of single sub-lethal dose (12 mg/kg body wt.) of cadmium chloride neutralizes endogenous hormonal activity in th male Indian Hanuman langur (Presbytis entellus entellus), resulting in a marked decrease in the production of androgens and subsequent reduction in the weights of sex accessory glands. Cadmium chloride in low dose (4 mg/kg body wt.) failed to bring about any significant change in the weights of excised tissue but did change biochemical composition and histo-architecture of testes. A significant increase in the concentration of testicular cholesterol was observed after the treatment. Decrease in the sialic acid concentration, total lipids and acid phosphatase activity of testis was associated with the degenerative changes of the spermatogenic elements. Reduced fructose and sialic acid concentration in the seminal vesicle of cadmium chloride treated animals indicate an inhibition of androgen production. Our results show that sialic acid epididymis is not androgen dependent in langurs. It is suggested that cadmium induced biochemical and histological changes in the testes and epididymides are dose dependent.