Aim: Patients with chronic hepatitis B and people with a history of hepatitis B (HBV) infection are at risk of HBV reactivation (HBVr) when they receive immunosuppressive therapy. In this study, we aimed to evaluate the hepatitis B serology, risk groups and antiviral prophylaxis of patients receiving various immunosuppressive therapies due to rheumatological diseases.
 Material and Method: The study included 375 patients over 18 years of age who received tumor necrosis factor-α (TNF-α) inhibitor, tyrosine kinase inhibitor, steroids, methotrexate or anti-CD20 antibodies due to rheumatic diseases in a training and research hospital between May 2022 and May 2023. Hepatitis B surface antigen (HbsAg), hepatitis B surface antibody (anti-Hbs), hepatitis B core protein antibody (anti-Hbc IgG) serologies, immunosuppressive therapies and oral antivirals were retrospectively analyzed.
 Results: The average age of the 375 patients included in the study was 43.77±13.07 years. 193 (51.5%) of the patients were male. 11 patients were HbsAg positive, 150 patients were anti-Hbs positive, 19 patients were isolated anti-Hbc IgG positive, and 79 patients were both anti-Hbs and anti-Hbc IgG positive. According to serological findings, 109 (29%) patients had HBV exposure. All three test results of 194 (51.7%) patients were negative. A total of 85 (22.7%) patients received oral antiviral prophylaxis due to the use of immunosuppressive agents. In terms of HBVr, 16.5% were evaluated as high risk, 75.3% as moderate risk, and 8.2% as low risk. Out of 85 patients 79 received entecavir, 5 reveived tenofovir disoproxil fumarate (TDF) and 1 received tenofovir alafenamide fumarate (TAF). The mean duration for the immunosuppressive therapy was 6.41±4.20 years. The mean duration of oral antiviral prophylaxis among patients was 1.02±1.72 years. HBVr was not observed in any of our patients.
 Conclusion: Before patients receive immunosuppressive therapy, hepatitis B serologies and prophylaxis indication should be evaluated firstly. In addition, as a preventive medicine activity, hepatitis B vaccinations of unvaccinated patients should be completed as quickly as possible.