Objective:to estimate the prevalence of serological markers for hepatitis B and C in patients with diabetes mellitus and analyze potential associated factors. Method:a cross-sectional study with 255 patients with diabetes mellitus. Demographic, clinical, and risk behavior factors for hepatitis B and C were selected. The markers HBsAg, Anti-HBc IgG, Anti-HBc IgM, Anti-HBs, and Anti-HCV were investigated. A questionnaire and venous blood collection and inferential statistical analysis were used. Results:16.8% of the patients had a total reactive Anti-HBc marker, 8.2% an isolated Anti-HBs, and 75% were non-reactive for all hepatitis B markers. No case of reactive HBsAg was found and 3.3% of the patients had a reactive anti-HCV marker. The prevalence of prior hepatitis B virus infection was directly associated with the time of diabetes mellitus and the prevalence of hepatitis C virus infection was not associated with the investigated variables. The prevalence of hepatitis B and C infection in patients with diabetes mellitus was higher when compared to the national, with values of 16.8% and 3.3%, respectively. Conclusion:the results suggest that patients with diabetes are a population of higher vulnerability to hepatitis B and C, leading to the adoption of preventive measures of their occurrence.