Health workers (HWs) play a pivotal role in preventative programmes being implemented to combat the steady increase in the prevalence of HIV infection and AIDS in Nigeria. We report on a questionnaire survey conducted in October, 1993 among 111 doctors, 92 nurses and 53 non-health workers at the University of Ilorin Teaching Hospital, Ilorin, Nigeria. The aim was to assess their knowledge of AIDS (for all groups) and the attitude of the HWs only towards the care of patients with AIDS (PWAs). Although important gaps in knowledge were found in all groups, doctors performed significantly better than non-health workers on 22 out of 23 knowledge items, and more than nurses on 8 of such items. Nurses scored significantly higher than non-health workers on 18 of the knowledge items and more than doctors on one knowledge item. About one in three nurses would hesitate to nurse a PWA, while half would not participate in birth delivery. Also, about a quarter of doctors would hesitate to treat a PWA while one in three would not carry out surgery despite adequate precautions. The findings compare favourably with those reported from other countries. However, they still indicate the need for a comprehensive AIDS education package to improve the knowledge base and allay fears for all groups and to prepare HWs for the important task of caring for PWAs.