The objective of this study was to identify activities and exposures during leisure that might be associated with the development of prostate cancer. We analyzed data derived from a population-based case-control study that was carried out in Montreal between 1979 and 1985. Men (>4000) were interviewed, including cases of prostate cancer, other cancers, and population controls. The present analysis was restricted to the subset, aged 45-70 years, who underwent face-to-face interviews in which aspects of activities and exposures during leisure were ascertained. There were 400 incident cases of prostate cancer and 476 population controls. We calculated odds ratios (OR) for prostate cancer, adjusted for age, ethnic origin, respondent status, family income, body mass index, cigarette smoking, and alcohol consumption. Home or furniture maintenance was associated with an increased risk [OR, 1.4; 95% confidence interval (CI), 1.0-1.9], as was painting, stripping, or varnishing furniture (OR, 2.1; 95% CI, 0.7-6.7). Exposure during leisure to metal dust was associated with prostate cancer (OR, 3.2; 95% CI, 1.0-9.9), as was exposure to lubricating oils or greases (OR, 2.2; 95% CI, 1.2-3.7) and exposure to pesticides or garden sprays (OR, 2.3; 95% CI, 1.3-4.2). These findings are consistent with results derived from studies of occupational exposures.