The detection of HBe antigen (HBeAg) in the sera of chronic HBV carriers is classically used as a marker of viral replication and therefore of development and infectivity of the disease. On this basis, it was used for the selection of patients for antiviral treatment. However, discrepancies between the presence of HBeAg and signs attesting to viral replication, namely HBV DNA and DNA polymerase, have been reported. We attempted to determine the prevalence of markers of viral replication in a group of patients with chronic active hepatitis associated or not with cirrhosis. All 41 patients were HBs Ag carriers; HBe Ag was present in 36 (88 p. 100), and HBV DNA in 28 (68 p. 100). A statistically positive correlation was found between the presence of cirrhosis and the absence of viral replication. In spite of the detection of HBe Ag, no direct signs of viral replication were observed in 30 p. 100 of patients, mainly those with cirrhosis. Therefore it is clear that the detection of HBe Ag alone cannot be considered as a sign of viral replication. Direct signs of viral replication should help to select patients for antiviral therapy, which should be started before the occurrence of cirrhosis.