Early and efficient prevention of occupational blood exposure at hospital requires knowledge of exposures and risks according to staff characteristics. Calculation of annual exposure rates and relative rates from personal and occupational data. The overall annual incidence was 3.5 per 100 workers per year; maximum for nurses and midwives (6.5); minimum for cleaners and paramedics (0.6). Exposures affected mainly nurses (57.81% of accidents, 12.12% of cohort) and occurred mostly in the surgical and the medical departments (26.34 and 25.20% of accidents). Men/women and students/physicians rate differences were not significant. Emergency and intensive care staffs had the highest relative rates (4.27 and 3.05) compared with maintenance staff. Nurses and laboratory staff were more exposed than physicians (3.76 and 2.30 times) were. Our results prompt prevention and training to be precisely focused and efficiently devised.