The effect of indomethacin in cadmium-induced rats on accessory sex organs and adrenal weights and testicular Δ5-3β-hydroxysteroid dehydrogenase (Δ5-3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD) activities were studied at 72 h. Subcutaneous injection of a single dose of 0.45 mg cadmium chloride/100 g b.wt. resulted in a significant rise in adrenal weight but decreases in accessory sex organs weight and the activity of Δ5-3β-HSD and 17β-HSD after 72 h of injection. Simultaneous administration of indomethacin and cadmium prevented the rise in adrenal weight and decreased activity of Δ5-3β-HSD and 17β-HSD and the weight of accessory sex organs. It is inferred that indomethacin can protect the impairment of adrenal and male gonadal functions induced by cadmium in rats.