The HIV/AIDS pandemic has become one of the most important public health problems in recent times and it is having a profound impact on the lives of infected people and their families. There is an acknowledged burden of HIV/AIDS in Nigeria. As the prevalence of HIV/AIDS infection rises, health care professionals worldwide can expect greater clinical exposure to infected patients. The care of people living with AIDS presents a significant challenge to the health care sector. This study seeks to explore the relationship between sources of HIV/AIDS information and knowledge, and the relationship between knowledge of HIV/AIDS and care for people with AIDS among health care providers in three different levels of health care institutions in the southern region of Nigeria. Health care workers from two states in southern Nigeria completed a questionnaire that was designed to assess knowledge, attitudes and practices about HIV/AIDS. The sample was composed of 277 (65%) females and 135 (31.7%) males. The results showed a fair level of knowledge among all health care professionals, with the highest level of knowledge among the doctors and the lowest among laboratory workers. There was a significant gender difference in the level of knowledge but the data suggested that knowledge did not differ by hospital settings. There were generally negative feelings and views about the care of HIV/AIDS patients among the professionals, these views being worst at the community health centers and best at the government hospital. The greatest source of information for the majority of professionals was health talks/seminars, and those respondents who got their information from school scored the highest on the items on general knowledge of HIV/AIDS incidence, cause, transmission, and clinical treatment. This has important implications for future interventions designed for health care professionals including doctors, nurses and laboratory workers.