AIM: Entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) are first-line nucleos(t)ide analogues for hepatitis B virus (HBV)-infected patients. However, consecutive TDF treatment causes renal dysfunction, and the safety and efficacy of TAF have not been established in severe renal dysfunction patients, including hemodialysis patients. The efficacy and safety of ETV in these populations has not been clarified. The study aimed to clarify this. METHODS: In this retrospective multicenter study, between 2006 and 2018, a total of 567 HBV-infected patients treated with ETV monotherapy were screened. Patients were included if >20 years old, treated with ETV monotherapy for >1 year, and had proper clinical information. The efficacy of ETV and changes in renal function were evaluated according to renal function. RESULTS: A total of 273 patients were included: 9.2% (25/273), 1.8% (5/273), and 3.7% (10/273) had chronic kidney disease (CKD) stage G3, CKD stage G4/5, and were on hemodialysis, respectively. Overall, 84.2%, 94.0%, and 96.2% of patients experienced serum HBV-DNA disappearance at 1, 2, and 3 years, respectively, after treatment initiation. In patients with CKD stage G3-5, estimated glomerular filtration rate tended to restore with time, which was in contrast to patients without renal dysfunction. The rate of disappearance in serum HBV-DNA, alanine transaminase normalization, and virological breakthrough was similar between patients with or without renal dysfunction. ETV showed high efficacy for all 10 hemodialysis patients without virological breakthrough. CONCLUSIONS: Entecavir for HBV-infected patients with severe renal dysfunction, including hemodialysis patients, is highly effective and does not affect renal function.