To analyze the incidence of occupational exposure to HIV in a large group of healthcare workers at the 2 Thai Red Cross hospitals, prospectively collected during a seven-year period in order to find out the causes and circumstances that prone to exposure, the interventions that may minimize the exposure and the consequences of the accidents. The first 200 incident reports from 198 hospital workers of the Thai Red Cross Society who had occupational exposure to HIV-infected blood and body fluids during 1991-1997 were analyzed. We analyzed the demographic data, the timing and place of exposure, the nature and cause of exposure, HIV status at baseline and at follow-up at 3, 6 and 12 months as well as the received antiretroviral prophylaxis. All of the 198 HCW had negative anti-HIV at baseline and remained negative throughout the one-year follow-up although only 55% submitted the results of their anti-HIV testing at 6 months. However, none claimed for work-related life insurance against HIV during those 7 years indicating that nosocomial rate of transmission is less than 1 in 200 or less than 0.5%. Analysis of the incidents indicated that the risk group was the 20-40 years old nursing personnel who worked in the medical wards during the regular working hours. The procedures that were responsible for most of the injuries were venepuncture, intravenous access, injection and waste collection. Most of the injuries could be prevented if the work place safety guidelines were strictly followed and if personnel were more careful at work. The results can be used to implement more effective preventive measures for hospitals in Thailand. Postexposure management at the Thai Red Cross hospitals conformed with the international guidelines. However, only 78% of those who should receive postexposure prophylaxis were recommended for treatment and only 69% of those recommended actually took the treatment. This emphasizes the need to educate clinicians involved in postexposure care as well as to ensure them and the injured subjects about the safety of the antiretroviral prophylaxis.