Objectives: Coronavirus disease-2019 (COVID-19) has affected more than 16 million people around the worldwide so far. Simultaneously, it has made the follow-up of chronic diseases difficult. We examined the course of co-infection with COVID-19 and chronic hepatitis B in this article and to reveal the vaccination status of these patients. Materials and Methods: Patients requiring oxygen therapy were classified as severe. Also, patients’ demographic and vaccination information was scanned using the hospital data system. Results: A total of 100 patients with chronic hepatitis B were included. There were 53 patients with polymerase chain reaction- confirmed COVID-19. Since these patients needed oxygen, 9 were admitted to clinics and 4 to the intensive care unit. Of 13 patients with severe disease, 5 had Sinovac, 2 had Pfizer-BioNTech, 1 had mixed vaccine, and 5 were unvaccinated. Severe disease was significantly lower in the Pfizer-BioNTech vaccinated group. Similarly, the longest interval between vaccine and COVID-19 disease was found in this group. Conclusion: The effect of COVID-19 and hepatitis B co- infection on the severity of COVID-19 and the long-term effects of vaccine-induced immunity in these patients will be guided by epidemiological studies. According to our study, it can be said that the type of vaccine is one of the factors affecting the severity of the disease. Although the number of patients is small, severe acute respiratory syndrome-coronavirus-2 and hepatitis B co-infection do not affect the more severe outcomes.