Biochemical indicators of renal dysfunction have been compared with liver and kidney cadmium levels measured by neutron activation analysis in a group of 37 cadmium smelters. Higher than normal concentrations of cadmium in the liver reflect past exposure; they were associated with evidence of renal dysfunction in workers exposed to cadmium for more than 10 years. A small group of 6 workers exposed to cadmium for only a short time (mean = 4.6 years) had high hepatic cadmium concentrations but normal renal function. Longitudinal studies are required to establish the natural history of renal dysfunction following cadmium accumulation in industrial workers.