Acute copper(II) sulfate poisoning in the mouse induces renal tubular degeneration and necrosis. Timely administration of sodium 2,3-dimercaptopropane-sulfonate (DMPS) effectively prevented the development of the morphological renal sequelae of copper intoxication. During the time course of this study (5 days), no copper-induced hepatic lesions were observed. DMPS and its preformed copper complex possess low inherent toxicity with no hepatorenal lesions occurring over a 5-day period. These findings suggest that DMPS may be an effective antidote in acute and chronic copper poisoning in humans.