Many infectious diseases in adults can be prevented by a life-long vaccination strategy'. Hepatitis B disease burden was shown to be higher in diabetic patients. American Advisory Committee on Immunization Practices recommends to vaccinate diabetic patients against hepatitis B since 2011. In this study, we aimed to determine hepatitis B virus serology status to determine the rates of diabetic patients who have indications for hepatitis B vaccination. The electronic database of the hospital was searched to identify adult patients aged above 18years and with hemoglobin A(1)C levels of 6.5% or above, who have been seen at General Medicine Outpatient Clinics of a university hospital during a 3-year period. A total of 5187 patients were included in the study. After exclusion of patients with an incomplete serological panel, 1358 patients were included for further analyses. Twenty-nine percent of the patients had indication for hepatitis B vaccination, whereas only 8% were vaccinated. This study showed that nearly one third of patients who had hepatitis B serological data had an indication for hepatitis B vaccination and this is a clear reflection of the need to keep a lifelong vaccination log and inquire vaccination data.