It is now generally acknowledged that all health care workers should be vaccinated against hepatitis B. To this end, a questionnaire was sent to 132 clinical dental students and 70 staff in August 1993 at a British dental hospital, to assess their vaccination status. Approximately 10% of subjects had not completed their course of immunisation. Furthermore a significant number of subjects had failed to follow up their vaccination by an antibody titre test. Our results suggest that approximately 1 in 7 cases failed to seroconvert, emphasising that mere vaccination may not offer sufficient protection against hepatitis B. Thus adequate cross-infection control measures must be maintained in the interest of all patients.