The ability of three chelating agents, dimercaptopropanesulphonate (DMPS), dimercaptosuccinic acid (DMSA), and diethylenetriaminepentaacetic acid (DTPA), to reduce the retention of platinum in the kidneys was tested in male Sprague-Dawley rats treated 24 h previously with Cisplatin. DMPS and DMSA, when given as four daily doses of 1 mMol/kg, increased the urinary excretion from 10.1%±1.2% to 13.6%±1.3% and 13.5%±2.6%, respectively, but only DMSA caused a small but significant reduction in the kidney platinum content. DTPA was totally ineffective. It is concluded that none of these agents is likely to be useful for the reduction of Cisplatin-induced renal toxicity in the clinical situation.