Seventy-seven definitely HIV infected children were identified at Ethio-Swedish Children's Hospital in Addis Ababa, Ethiopia, between January 1990 and April 2000. There were 39 females and 38 males. Their age ranged from 15 months to 12 years and their median age was 3.8 years. Most commonly diagnosed diseases included disseminated tuberculosis seen in 28 patients, pneumonia in 27, pulmonary tuberculosis in 19, persistent or chronic diarrhoeal disease in 21, otitis media in 17 and marasmus in 17 patients. Pneumocystic carinii pneumonia was considered in 11 patients. One patient was suspected to have lymphoid interstitial pneumonitis. Sixteen children (21%) died in hospital. There was an abandoned child and 20 children were already orphans. All patients presented with clinical opportunistic infections and thus there is a need to develop a pediatric clinical guideline for patient management. Primary prevention of HIV infection in women of the child bearing age is of paramount importance and reduction of mother-to-child transmission of HIV infection by antiretroviral drug needs to be considered as a primary prevention for a child.