We have studied HBV markers in 56 sera from 56 prostitutes who were registered to the Health Ministry Zonal Hospital of Chimbote on October, 1987. We used micro-Elisa solid phase technics to study the HBs Ag, HBs Ab, HBc Ab (Total IgG) and HBe Ag markers. From them, 89.3% were positive to any marker: 5.4% were asypmtomatic carriers and 83.9% had markers related to past HBV (immunity). In conclusion, this data shows clearly, that the prostitutes represent an important risk group for the transmission of the Hepatitis Type B virus to people who maintains sexual relations with them. The HBc Ab was the best marker to detect HBV antibodies, that did it in 95.7%.