The effect of lamivudine treatment on the outcome of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis is unclear. In a retrospective multicenter study, we have analyzed the virological events observed during lamivudine therapy in patients with HBeAg-negative chronic hepatitis and evaluated the correlation between virological response and clinical outcomes. Among 656 patients (mean age 49.1 years) included in the database, 54% had chronic hepatitis, 30% had Child-Turcotte-Pugh (CTP) A cirrhosis, and 16% had CTP B/C cirrhosis. On therapy (median 22 months, range 1–66), a virological response was obtained in 616 patients (93.9%). The rate of maintained virological response was 39% after 4 years. During follow-up, 47 (7.2%) patients underwent liver transplantation, liver disease worsened in 31 (4.7%), hepatocellular carcinoma (HCC) developed in 31 (4.7%), and 24 patients (3.6%) died of liver-related causes. Patients who had cirrhosis and who maintained virological response were less likely than those with viral breakthrough to develop HCC (P < .001) and disease worsening (P < .001). Survival was better in CTP A patients with cirrhosis and maintained virological response (P = .01 by rank test). Multivariate analysis revealed that presence of cirrhosis and viral breakthrough were independently related to mortality and development of HCC. In conclusion, lamivudine is highly effective in reducing viral load in HBeAg-negative patients. After 4 years of therapy, 39% of patients maintain a virological and biochemical response. Loss of virological response may lead to clinical deterioration in patients with cirrhosis. (Hepatology 2004;40:883–891).