The efficacy of human lymphoblastoid interferon (Wellferon) was studied in 25 patients with anti-HBe positive, HBV DNA positive chronic hepatitis B. The patients were randomized to receive 5 MU/m2, three times weekly or no treatment for 6 months. The study is ongoing and to date 19 patients have been followed up for more than 3 months and 14 for more than 6 months. At 9 months, serum HBV DNA had become negative and ALT levels normalized in 57% of interferon-treated patients. This compared with 33% becoming serum HBV DNA negative and 16% with ALT normalization in the untreated group. Clearance of HBV DNA in interferon treated patients was not consistently associated with the appearance of transaminase peaks during therapy, in contrast with those seen in HBeAg positive patients. The preliminary results of this trial suggest that interferon reduces HBV replication in anti HBe/HBV DNA positive patients with chronic hepatitis B.