A free-of-charge vaccination program against hepatitis B, in which plasma-derived vaccine was used, was offered to 1,299 hospital personnel of Chulalongkorn University Hospital, Bangkok. The initial acceptance rate for vaccination was 65.7%, with 10.0% nonacceptance and 24.3% undecided. The highest rates of acceptance were among medical students (75.5%), student nurses (68.8%), and newly graduated nurses (63.6%). The lowest rate of acceptance was among physicians (48.2%). Factors strongly associated with the acceptance of vaccination were nature of work, age of personnel (less-than-or-equal-to 40 yr), number of years spent in profession (less-than-or-equal-to 15 yr), knowledge of hepatitis B, confidence in vaccine efficacy and safety, no history of hepatitis B infection, and contact with blood or blood product. Different types of fear, as well as lack of knowledge, were the main reasons responsible for 46.2% of all refusals. More specific educational efforts about vaccine safety and efficacy may positively influence the acceptance of hepatitis vaccination program among health care personnel.