This study was performed to study the immune response to hepatitis B virus (HBV) vaccine in health-care workers. Through a cross-sectional study, relevant information and blood samples from 151 healthcare workers at the Firuzgar hospital were studied. The age range of the study individuals was 20-59 years, with the mean and standard deviation being 35.11 and 10.06, respectively. There were 24 males (15.9%) and 127 females (84.1%). The mean and median of months after HBV vaccination was 63.42 and 49.00, respectively. The mean and median of anti-HBs titer in those who received HBV vaccination was 164.81 and 200 milli international units per milliliter (mIU/mL), respectively. Of the 129 HBV-vaccinated subjects, 103 (68.2%) had anti-HBs titer >10 and 26 (17.2%) had anti-HBs titer <10. There was no association between gender and anti-HBs titer, but vaccination and adequate completion of its courses were associated with higher anti-HBs titer (P < 0.05). Also, the logistic regression method showed that the association between duration after vaccination and age with anti-HBs titer was not statistically significant. Our study suggests that the HBV vaccine immunization program had obtained excellent efficacy. There is need for further investigation among subjects who are not vaccinated against HBV but are positive for anti-HBs as well as in HBV-vaccinated subjects with low anti-HBs titers, about possible low-level viremia and other causes of lower vaccine efficacy, particularly in health-care workers.