Occupational pollutants may have a role in development of chronic renal failure (CRF). Most epidemiological studies have been cross-sectional, limited to certain renal diagnoses, or concentrated on early transient renal effects. In a case-control study, we examined the association between CRF and occupational exposure. Occupational histories of 272 men and women with CRF (of all types) were compared with those of 272 controls matched for age, sex, and region of residence. Exposures were assessed and degree and frequency were scored independently by three industrial hygienists unaware of case/control status. Significantly increased risks of CRF were found for exposure to lead (odds ratio 2.11 [95% CI 1.23-4.36]), copper (2.54 [1.16-5.53]), chromium (2.77 [1.21-6.33]), tin (3.72 [1.22-11.3]), mercury (5.13 [1.02-25.7]), welding fumes (2.06 [1.05-4.04]), silicon-containing compounds (2.51 [1.37-4.60]), grain dust (2.96 [1.24-7.04]), and oxygenated hydrocarbons (5.45 [1.84-16.2]). The frequencies of various occupational exposures were high among patients with diabetic nephropathy. This epidemiological study confirms previously identified risk factors and suggests that additional occupational exposures, for which there is some other experimental evidence, may be important in the development of CRF. The role of grain dust and the association between occupational exposure and diabetic nephropathy merit further investigation.