ARTIGO/ARTICLEAs infecções causadas pelo vírus da hepatite B (VHB) e pelo vírus da hepatite C (VHC) constituem grave problema de saúde pública mundial 9 . ABSTRACTHepatitis B and C continue to be important public health problems in Brazil. In this study, the prevalence of serological markers for hepatitis B and C in individuals from the State of Pará, attended at the Central Public Health Laboratory of Pará between January 2002 and December 2005, was determined. 11,282 tests to investigate HBsAg, 2,342 for anti-HBc and 5,542 for anti-HCV were performed. The prevalence of HBsAg was 3.6% and it was predominantly found in the age range of 20 to 29 years old, while anti-HBC was observed in 37.7% of the subjects. The prevalence of anti-hepatitis C virus was 3.6% and it was predominantly found in individuals over 50 years old. Thus, the frequencies of the markers found in Pará were higher than many other states in Brazil, hence suggesting that there is a need for public health measures of greater effectiveness for combating these illnesses in this region.Key-words: Hepatitis B. Hepatitis C. Serological markers. Prevalence. Infections.3 padrões: baixa (<1%), intermediária (1 a 5%) e alta (>5%) 5 . A soropositividade para o HBsAg e anti-HBc variam de região para região e em grupos populacionais específicos.A transmissão do VHB pode se dar horizontalmente através de contato com fluidos orgânicos contendo vírus, de modo especial com sangue, sêmen e saliva 9 . A maior prevalência está relacionada aos fatores de risco: hemodiálise, multitransfusões de sangue ou hemoderivados, manipulação de sangue humano, acidentes com materiais perfuro-cortantes, convivência íntima com infectados, uso de drogas ilícitas e contato com múltiplos parceiros sexuais 2 . A transmissão vertical ocorre através da passagem do vírus da mãe diretamente para o recém nascido no parto 14 . O vírus da hepatite C é transmitido essencialmente por contato com sangue,