Introduction: Little is known about occupational agents andthe occurrence of leukemia and myelodysplastic syndromein Brazil. Objective: The aim of this study was to trace thesociodemographic and occupational profiles of patients withleukemia and myelodysplastic syndrome in two hospitals inthe city of Rio de Janeiro, Brazil. Methods: We carried out astudy of 229 cases from the period 2000 to 2006. Interviewswere conducted with patients to obtain information onfamily history, lifestyle risk factors, occupational history,residential history, and occupational and non-occupationalexposures by using a structured questionnaire. The frequencyand duration of occupational activities related to exposureamong participants were estimated. Each individual’s levelof exposure was classified as low, moderate, high or veryhigh. Results: The main exposures observed were to chemicalcleaning and disinfectant products, followed by gasolineand lubricating oil. Most of the exposures occurred at lowfrequencies. However, for benzene, solvents, thinners, andcoal combustion, the highest prevalence was observed formoderate exposures. Furthermore, it was observed that theexposure patterns of substances varied for each group, suggestingthat the intensity of exposure was determined byspecific types of substances. Conclusion: The monitoring ofexposure in occupations that deal with solvents is critical, inorder to reduce the incidence of leukemia. Since occupation isa preventable risk factor, strategies for primary prevention andhealth promotion in the workplace should be a top priorityin cancer prevention policies in Brazil.Keywords: Leukemia; Occupational Health, Myelodysplasticsyndromes, Epidemiology.