Data on sociodemographic status, health beliefs, knowledge of hepatitis B, experience with prior vaccinations, health locus of control, and desire to receive hepatitis B vaccine were assessed in 1,500 hospital employees. Twenty per cent of the variance of the decision to accept vaccine could be explained; beliefs about the safety and efficacy of vaccine influenced acceptance most. Beliefs concerning the likelihood of contracting hepatitis B and the chance of becoming severely ill were less important determinants of vaccine acceptance. Additional factors studied, including knowledge, experience with vaccinations, and sociodemographic status, were important independent determinants of health beliefs. We conclude that the beliefs of health care providers, particularly regarding the safety and efficacy of hepatitis B vaccine, have a major impact on their decision to accept or reject vaccine. Health education interventions may be most effective when addressing beliefs about vaccine safety and efficacy.