OBJECTIVE: To analyze the effect of diabetes on general and cardiovascular disease (CVD) mortality and morbidity in southern Brazil. RESEARCH DESIGN AND METHODS: A population-based cohort study of 1,091 individuals was conducted. Diabetes was ascertained by medical history. The vital status of 982 individuals and the incidence of events were ascertained during another visit and through hospital records, death certificates, and verbal necropsy with relatives. RESULTS: The mean +/- SD age of participants was 43.1 +/- 17 years, and 55.7% were women. The prevalence of diabetes was 4.2%, and the mean follow-up time was 5.3 +/- 0.07 years. Mortality was 36.3% and 6.6% in participants with or without diabetes, respectively; the incidence of CVD was 20.8% and 3.0%, with an adjusted hazard ratio of 4.4 (95% CI 2.4-7.9). Diabetic population-attributable risk (PAR) for CVD mortality was 10.1% and 13.1% for total CVD. CONCLUSIONS: Diabetes is responsible for a large PAR for overall mortality and cardiovascular events in Brazil.