Occupational risk of bladder cancer (including papilloma) was investigated as part of a case-referent study in Copenhagen. Occupational histories were obtained on 389 cases and 790 referents drawn at random from the general population of the study area. When persons with missing information were excluded, a total of 371 cases (280 men, 91 women) and 771 referents (577 men, 194 women) were left for analysis. After adjustment for tobacco smoking, age, and sex, significantly increased relative risks were observed for occupation in land transport, in particular bus, taxi, or truck driving. A statistically significant trend was seen with duration of employment in these trades. Based on a logistic regression analysis, a relative risk (RR) of 1.3 was determined for 10 years of employment in the trade. An association was also found for employment in trades undertaking painting (RR = 1.4 for 10 years' employment), and a significant trend emerged for duration of employment. A positive association with employment in the textile and leather industry disappeared after adjustment for tobacco smoking, and no association with duration of employment emerged. No association was found with employment in the chemical, rubber, iron and metal industries or in health services.