Chronic hepatitis B (CHB) is a common infectious disease that represents one of the main causes of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). CHB is still difficult to treat due to  the lack of drugs that completely eliminate hepatitis B virus (HBV) from hepatocytes. The study was aimed to describe the CHB clinical and laboratory features, assess the efficiency of antiviral therapy and identify the factors associated with the response to antiviral therapy. The results of clinical and laboratory assessment, instrumental examination, serological and molecular testing of the patients (n = 201) followed up between 2007–2021 in the Viral Hepatitis Diagnosis and Treatment Center at the Clinical Hospital No. 85 of FMBA of Russia were assessed based on primary sources. Most of the patients in the group were males (56.7%); the HBeAg-negative patients predominated (93%). LC was diagnosed in nine patients (4.5%), among them one patient had HCC. The HBV D genotype was determined in 95.4% of cases, А genotype in 3.1% of cases, and С genotype in 1.5% of cases. After a year of treatment with the nucleos(t)ide analogues (entecavir or tenofovir) 88% of patients showed no viremia and their biochemical parameters were back to normal (88%). The overall seroconversion rate was 41.7% for HBeAg and 3% for HBsAg. Thus, high rates of virological response and enzyme activity normalization were obtained. Low baseline viremia level is an independent prognostic factor of achieving a virological response. The HBsAg level in the end of therapy makes it possible to predict relapse after the treatment cessation.