In order to improve educational programmes directed at health care workers we investigated their knowledge, attitudes and practices in relation to HIV/AIDS. An anonymous self-administered questionnaires was distributed to 609 health care workers. Of these, 59.6% agreed to participate (42.4% of the medical doctors, 74.3% of the nurses and 79.6% of the laboratory technicians, health visitors and other health care workers). All studied groups believed that their knowledge of HIV modes of transmission (84.3%) was sufficient. In contrast, a relatively small percentage reported knowledge of the clinical spectrum of HIV infection (48.8%) and the diagnostic assays (57.6%). Nearly all the study participants believe (92.8%) that there is a risk of acquiring HIV infection during the hospitalization of HIV/AIDS patients. Obligatory screening of all patients was reported by nearly all participants (90.6%) as a chance to minimize their occupational risk. Although health care workers reported satisfactory knowledge of safety measures (87.0%), only 56.7% used gloves and 38.8% accept the hospitalization of HIV/AIDS patients. In spite of the educational programmes for AIDS in Greece, this study demonstrates that health professionals' knowledge and precautionary measures are not sufficient. As a result, a small percentage of them treat AIDS patients without discrimination. There is an urgent need to implement specific educational programmes for health professionals so that they will safely provide high quality care to people affected by HIV/AIDS.