The efficacy of adenine arabinoside (Ara-A) alone or in combination with prednisolone utilizing its withdrawal effect was studied in 43 patients with deoxyribonucleic acid polymerase- and hepatitis B e antigen-positive chronic hepatitis. Ten patients were treated with 10 mg/kg body wt of Ara-A alone for 4-8 wk. In 9 cases, prednisolone (40 mg/day) was given at a constant dosage for 4 wk before Ara-A treatment. Fourteen patients received oral prednisolone alone for 4 wk, and 10 patients served as untreated controls. Six of 9 patients (67%) undergoing the combination therapy became seronegative for hepatitis B e antigen, whereas only 4 of 24 patients (17%) treated either with Ara-A alone or prednisolone alone lost the antigen. Two of the 10 untreated patients became seronegative for hepatitis B e antigen during the same follow-up period of 9 mo. This prospective controlled study suggests that the combination of immunomodulation by steroid withdrawal and subsequent Ara-A is more effective in the treatment of patients with chronic liver disease and active hepatitis B virus replication than treatment with Ara-A alone.