- Background: Kaposi's sarcoma (KS) is commonly associated with the acquired immunodeficiency syndrome (AIDS) in adults. Little is known regarding its occurrence in children. Objective: Our purpose was to report the clinical and epidemiologic characteristics of KS in three Romanian children with AIDS and to compare them with previously reported AIDS-associated KS in children. Methods: This was a clinicopathologic study and computer-based literature review. Results: All three Romanian children had skin involvement; two had involvement of lymph nodes and internal organs. All had acquired human immunodeficiency virus (HIV) infection postnatally. Including these children, 33 cases of AIDS-associated KS in children have been reported. Thirteen of 30 evaluable patients had acquired HIV infection postnatally; nine of these children (69%) had cutaneous involvement by KS. A perinatal route of transmission was present in the remaining 17 cases; only two of these children (12%) with KS had cutaneous involvement. No case was noted in which intravenous drug use was the sole parental HIV risk factor. Conclusion: The data support the contention that KS is caused by a second infectious agent prevalent only in certain HIV-infected populations. Children of parents in high-risk groups for KS and children who acquire HIV via contaminated blood or blood products are at highest risk for KS. The route of acquisition of HIV infection may also be associated with different clinical manifestations of KS in children.