Background: Health care workers (HCW) are always at risk of hepatitis B. This study was carried out to evaluate the response to hepatitis B vaccination and determine Anti HBs Antibody serum level in the vaccinated HCW.

Materials and Methods: This descriptive study was performed in 128 HCW of Beheshti Hospital who were vaccinated against hepatitis B virus. Titer of Anti HBs antibody was determined by ELISA method. Statistical analysis were accomplished by using Chi-square, Fisher exact test.

Results: 60.1% of HCW were females and the rest were males (39.9%). The titer of Anti HBs was above 100IU/lit (good responder) in 73 cases (57%), between 10-100IU/lit (low responder) in 33 cases (25.8%), and lower than 10IU/lit (non responder) in 22 cases (17.2%). 81.8% of the females and 84.3% of the males were responders. 18.2% of the females and 15.7% of the males were nonresponder. There was no statistically significant correlation between age/sex and Anti HBs titer. But there was a significant statistical correlation between the interval of the last vaccination and Anti HBs titer.

Conclusion: Enough level of Anti HBs antibody was detected in the majority of personnels . There was no statistical correlation between age/sex and Anti HBs titer but there was significant correlation between Anti HBs titer and the time.