OBJECTIVE: The objective of this study was to examine the associations between socioeconomic/occupational factors and histologic subtypes of leukemia. METHODS: The Swedish Family-Cancer Database was used to calculate standardized incidence ratios for different social classes and occupational groups. RESULTS: The overall standardized incidence ratio was close to unity between different socioeconomic groups, except for female manual workers with a significantly decreased risk. Among male occupations, increased risks were noted for sales agents, seamen, and chemical process workers. For female occupations, increased risks were observed among mechanics, iron and metalware workers, hairdressers, and launderers and dry cleaners. CONCLUSIONS: The present study suggests that socioeconomic/occupational factors have a minor effect on the risk of leukemia. Occupational groups with possible exposure to organic solvents and other chemicals such as chemical process workers, mechanics, iron and metalware workers, and launderers and dry cleaners may entail true risk for leukemia.