In a hospital-based case-control study of 124 (105 male and 19 female) histologically confirmed malignant mesothelioma cases and age- and sex-matched controls, the role of cigarette smoking and the risk of asbestos exposure was investigated. Exposure to asbestos for at least 1 year was likely for 78% of male cases and 16% of female cases, and 90% of males were possibly exposed. Male cases worked predominantly in the ship-building industry, construction, or insulation trades. Elevated risks were found for males employed in asbestos-related industries [odds ratio (OR) 8.1; 95% confidence interval (CI) 4.9-13.5], e.g., shipyards (OR 82.9, 95% CI 25.5-269.1), construction/maintenance (OR 8.3, 95% CI 4.6-14.8), and other asbestos-related jobs (OR 3.2, 95% CI 1.4-7.2), and for males who self-reported exposure to asbestos or insulation (OR 50.9, 95% CI 21.7-119.8). A statistically significant trend was found for the risk of mesothelioma with increasing years employed in non-shipyard asbestos-related occupations. Among women, only one case worked in an asbestos-related industry and two reported domestic contact with asbestos. No association between cigarette smoking and mesothelioma was found for either men or women. We also report the occurrence of mesothelioma in occupations which have not been previously reported.