<span name="style_bold">Objectives: </span>The main objective was to establish the seroprevalence of hepatitis B, C and Human Immunodeficiency Virus in the homeless population and also to identify the risk factors for the presence of such infections. <span name="style_bold">Methods: </span>A descriptive exploratory, transversal and prevalence study was conducted with blood sampling in a population of homeless people who attended a social assistance centre located at Merced district in the city of San José, during 2011. <span name="style_bold">Results: </span>High prevalence of hepatitis B (16 %) of HIV disease (7%) and hepatitis C (4%) was found. Cases of hepatitis B mostly correspond to prior infection by this virus. There was only a case of hepatitis B active due to the presence of surface antigen and two cases listed as possible HBV/HIV co-infections. <span name="style_bold">Conclusions: </span>Studied population showed a high prevalence of previous hepatitis B and HIV infection, however, the presence of hepatitis C was not prevalent.Studied population showed a high prevalence of previous hepatitis B and HIV infection, however, the presence of hepatitis C was not prevalent.

Homeless Person; Alcoholism; Drug Users; Hepatitis B; Hepatitis C; AIDS Serodiagnosis