The aim of this multicenter, cross sectional study was to assess the prevalence, incidence and associated risk factors among incarcerated populations from twelve Brazilian prisons. The total of 3,368 individuals from twelve prisons was randomly recruited between March 2013 and March 2014. Participants were interviewed, and provided blood samples which were tested for antibodies to Hepatitis C (HCV ab). One year after the first investigation, a cohort study was conducted with 1,656 inmates who participated the cross sectional study. Positive samples were tested for the presence of HCV RNA. Out of 3,368 inmates, 520 (15.4%) were females, and 2,848 (84.6%) were males. The overall prevalence of HCV was 2.4% (95% CI: 1.9 to 2.9), with 0.6% (95% CI: 0.4 to 0.8) in females, and 2.7% (95% CI: 2.1 to 3.3) in males (p