Because of the potential geographic variation in prevalence and exposure to hepatitis B virus and the high cost of hepatitis B immunization, we performed serologic screening on prehospital care personnel in Salt Lake City, Utah. All individuals screened had been in a line (street) position for at least five years. Their average age was 38.5 years. One of the 50 paramedics and none of 110 emergency medical technicians had serum antibody to hepatitis B surface antigen (0.6%; 95% confidence limits, 0.03 to 3.53%). Because the estimated annual incidence based on the observed prevalence is less than 1%, we conclude that exposure to hepatitis B virus is not a major occupational hazard for these employees in our area.