Abstract: ters.The diagnosis of CHB infection was made on the basis of biochemical, serological and histological data, when available.Seventy and six percent of the patients were nucleos(t)ide naïve.Virological response was defined as undetectable serum HBV DNA level (<200 copy/ml) by COBAS Taqman (Roche Diagnostics, Mannheim, Germany).Safety issue was analyzed based on renal function.Results: Median age was 47.0 years.At baseline, 32% of the patients were HBeAg positive, 38% had cirrhosis, 201 patients were treated with ETV and 310 were treated with TDF based on the discretion of investigators.There were no significant differences in terms of the baseline characteristics observed between two treatment groups except initial higher serum AST (p=0.001),GGT (p=0.007) and HBV DNA levels (p=0.001) in ETV treatment group.Overall virological response rates in ETV and TDF treatment groups were 60% vs 58% (p>0.05),81% vs 70% (p=0.017),84% vs 77% (p>0.05) and 86% vs 84% (p>0.05) at 24, 48, 72 and 96 weeks, respectively.In NUC-naïve group, response rates were 59% vs 59% (p>0.05),81% vs 72% (p=0.042),84% vs 78% (p>0.05) and 86% vs 85% (p>0.05) at 24, 48, 72 and 96 weeks, respectively.With logistic regression analysis, after adjusted age and gender, ETV treatment (p=0.039,OR: 1.72) and HBeAg negativity (p=<0.001,OR: 3.69) were predictive factors for undetectable HBV DNA at week 48.Primary non response (< 1 log10 decrease) at week 24 was observed in 2% (2 ETV, 7 TDF) and partial virological response at week 48 in 25% of the patients (19% ETV vs 29% TDF, p=0.011).HBeAg loss was achieved in 23 of HBeAg positive patients.The cumulative probability of HBeAg loss was 10.9% and 20.4% at weeks 48 and 96, respectively.HBsAg loss was achieved in 2 patients.Hepatocellular carcinoma developed in 10 cirrhotic patients.Both treatments were well tolerated, no serious adverse event was observed.From baseline to the end of the 96 weeks, no significant difference in terms of the serum creatinine levels was observed between two treatment groups (median 0.87 mg/dL vs 0.87 mg/dL in ETV group and 0.82 mg/dL vs 0.84 mg/dL in TDF group (p>0.05).Conclusions: This study confirms that ETV and TDF suppressed HBV viral replication in CHB patients with/without cirrhosis in clinical practice.Both drugs are safe and tolerable in such patients.