The reduction of palladium, rhodium and neodymium ions at concentrations of 0.94, 0.97 and 0.69 mol dm(-3), respectively was studied in 1 mol dm(-3) HNO3 or 1 mol dm(-3) HCl, at a stainless steel and a vitreous carbon electrode, at 25 A degrees C. At a vitreous carbon electrode in a solution containing rhodium and palladium ions in 1 mol dm(-3) HCl electrolyte, the reduction of metal ions occurred at a similar potential to the formation of hydrogen gas, which impeded the selective separation of the two metals. At a stainless steel cathode in 1 mol dm(-3) HNO3, palladium deposition occurred at a potential a parts per thousand 0.35 V less negative than that of rhodium allowing the selective recovery of palladium. Neodymium ions were not electroactive in acidic chloride or nitrate media at pH 0. Using a solution obtained from a catalytic converter manufacturer containing palladium, rhodium and neodymium ions in 1 mol dm(-3) HNO3, palladium ions were preferentially removed at 0.15 V versus SHE at an average cumulative current efficiency of 57%.