Chronic hepatitis B infection is an important cause of liver-related mortality in China. This study assessed the efficacy and safety of entecavir in a heterogeneous patient population from a real-world' clinical practice setting in China. This prospective, observational cohort provides 48-week data on 2600 patients from 50 sites in China who received entecavir (0.5 or 1.0mg) and were assessed for virologic, serologic and biochemical responses. Patients were nucleos(t)ide-naive or -experienced and had compensated or decompensated liver function. At Week 48, 1545/2424 (64%) patients with compensated liver disease and 30/44 (68%) patients with decompensated liver disease achieved HBV DNA <50IU/mL. Greater proportions of nucleos(t)ide-naive than nucleos(t)ide-experienced (69% vs 53%), and adefovir-experienced than lamivudine/telbivudine-experienced (62% vs 52%) patients achieved this endpoint. Most patients with HBV DNA <50IU/mL also achieved HBV DNA <12IU/L (60%, 45% and 61% of nucleos(t)ide-naive, nucleos(t)ide-experienced and decompensated patients, respectively). In patients with compensated liver disease, ALT values normalized in 1532/1792 patients (85%), and HBeAg loss and HBeAg seroconversion were observed in 17% and 15% of treatment-naive and 15% and 11% of treatment-experienced patients. Entecavir was generally well tolerated. Adverse event rates were comparable between treatment-naive and treatment-experienced patients with compensated liver disease, but were higher in decompensated than in compensated patients, consistent with previous reports in these patients with more advanced disease. Four patients discontinued treatment due to adverse events. In a real-world' setting, entecavir was efficacious and well tolerated throughout 48weeks in a heterogeneous Chinese CHB population.