Sera of 103 carriers of hepatitis B surface antigen were assayed for e-antigen and anti-e. Twenty-four were e-antigen-positive, 31 anti-e-positive, and 48 had neither detectable (e-negative). Aminotransferases were elevated in 75% of the e-antigen-positive carriers compared with 25% of e-negative carriers (P less than 0.001) and 13% of anti-e-positive carriers (P less than 0.001). Serum DNA polymerase activity was significantly higher in the e-antigen-positive carriers than in carriers without e-antigen. Dane particles were shown in 10 of 12 carriers with e-antigen, compared with one of 12 e-negative carriers (P less than 0.0003) and none of 12 anti-e-positive carriers (P less than 0.00003). These results suggest that ongoing hepatitis B viral replication is more active in e-antigen-positive carriers than in carriers without e-antigen, a finding that may help explain the high prevalence of chronic active hepatitis described in these individuals.