Total HAV and HBc seroprevalence rates in two socioeconomic groups in Macaé, Rio de Janeiro State, Brazil, were estimated in 1,100 surplus serum samples from routine laboratory tests identified by sex, age, neighborhood, and category of medical care, i.e., the public health system or National Unified Health System (SUS) as compared to private health services (NSUS). Seroprevalence rates by age, 95% confidence intervals, and statistical significance tests for differences between SUS and NSUS are presented. Distribution of seroprevalence rates (P) for total HAV (P = 88.8%; 95% CI = 86.8-90.6) and total HBc (P = 15.3%; 13.2-17.6) by age showed an ascending curve. Prevalence rates in the SUS group were significantly higher that in the NSUS group, for both HAV (chi2 = 31.15; p < 0.0001) and HBV (chi2 = 15.41; p < 0.0001). The high prevalence rates reflect the epidemiological pattern of HAV infection in developing countries and the relevance of the social and environmental context. The proportion of susceptible individuals in the < 5 and > 20 year groups highlights the need to vaccinate for hepatitis A and the potential increase in severe cases. High HVB prevalence among adolescents underscores the importance of vaccinating this group. The results serve as a reminder to health professionals concerning biosafety norms.