BACKGROUND/AIMS: Entecavie (ETV) has a potent antiviral effect and low rates of resistance in hepatitis B virus (HBV) and is the first-line monotherapy in patients with HBV-related decompensated cirrhosis. We evaluated the efficacy of 12 months treatment with ETV and tried to determine predictive factors of response. METHODS: Forty-five consecutive decompensated cirrhotic patients who received ETV (0.5 mg/day) for more than six months were included. All patients were positive for HBV DNA, and the Child-Turcotte-Pugh (CTP) scores were over 8 point. Seventeen patients were HBeAg-positive. CTP score, model for end-stage liver disease (MELD) score, serum markers of liver function and HBV DNA were assessed every 3 months. RESULTS: ETV treatment for 12 months resulted in improvement of CTP and MELD scores. Pre-treatment mean CTP and MELD score were decreased from 10.1 (+/-2.0) and 13.48 (+/-4.05) to 7.24 (+/-2.0) and 9.68 (+/-4.85) at 12 months, respectively. The 1-year cumulative rates of HBV DNA negativity and HBeAg loss were 88.9% and 52.9%, respectively, by intention-to-treat analysis. Thirty-two (71.1%) showed improvement in CTP score. Eleven patients did not show change, and 2 patients got worse. The AST/ALT, albumin, bilrubin, prothrombin time were significantly normalized within six months. The good responder group had high level of prothrombin time than the poor responder group (p=0.004). CONCLUSIONS: Our result shows that entecavir can improve liver function in about 70% of patients with HBV related decompensated liver cirrhosis. INR may be a predictive factor of good response with entecavir in these patients.