OBJECTIVE To determine the incidence of needlestick injuries and the prevalence of hepatitis B vaccination among medical students, dentistry students, and hospital staff. DESIGN AND SUBJECTS Anonymous survey of final year medical students and dentistry students enrolled at Sydney University in 1992, and nursing staff and doctors employed in the wards and emergency department of Royal Prince Alfred Hospital, Sydney. RESULTS During their clinical training, 22% of medical students and 72% of dentistry students had received one or more contaminated, penetrating "sharps" injuries. Of hospital staff, 50% of ward nurses, 71% of ward doctors, and 50% of emergency staff had received this type of injury during the previous two years. Students were significantly more likely to be vaccinated against hepatitis B than hospital staff (P < 0.001)--98% of medical students and 95% of dentistry students had received a full course of vaccination. The rate of vaccination among hospital staff ranged from 79% in emergency staff to 85% in ward nurses. CONCLUSIONS Clinical students sustain needlestick injuries at a rate comparable with hospital personnel and therefore face a significant risk of exposure to transmissible pathogens, including hepatitis B virus, HIV, and hepatitis C virus. The rate of hepatitis B vaccination is high among clinical hospital staff and almost universal among medical and dentistry students.