During one year, 358 Chinese patients with chronic hepatitis B were enrolled in a lamivudine study: 142 received 25 mg daily, 143 received 100 mg daily, and 73 received a placebo. The end point of the study was a reduction in the necroinflammatory score (by at least 2 points in Knodell score) on pre- and post-treatment liver biopsies. This study was completed by 96% of the enrollees. Necroinflammatory score improved in 56% of patients in the 100 mg group, 49% in the 25 mg group, and 25% in placebo patients. Inflammation worsened in 7-8% of drug recipients, compared to 26% of patients on placebo. In patients receiving 100 mg lamivudine, fibrosis was significantly reduced, 16% converted from HBeAg positive to HBeAb state, with undetectable HBV DNA, compared to 4% seroconversion in the placebo group. Viral suppression determined by median reduction of HBV DNA by 98% during 52 weeks of the study also occurred in the patients receiving 100mg. In this one-year study, lamivudine was associated with substantial histologic improvement in many patients with chronic hepatitis B and a daily dose of 100 mg was well- tolerated and most effective.