BACKGROUND Kaposi's sarcoma is the most common neoplasm in patients with human immunodeficiency virus (HIV) infection. Although the best therapeutic approach is still unclear, patients with advanced KS are usually treated with systemic chemotherapy. METHODS A prospective multiinstitutional Italian study evaluated the efficacy and toxicity of combination chemotherapy with doxorubicin, bleomycin, and vindesine (ABVi) in patients with progressive and extensive HIV-related KS. Patients were given doxorubicin, 20 mg/m2 on Day 1; bleomycin, 15 mg on Day 1, and vindesine, 4 mg on Day 1 biweekly +/- granulocyte-colony stimulating factor. RESULTS Overall, 21 of 38 evaluable patients (55%) achieved an objective response (OR): there was 1 complete response and 20 partial responses. The most important bone marrow toxicity was granulocytopenia in 61% of the evaluable patients; 34% had Grades 3-4 toxicity, according to the World Health Organization Classification. The majority of patients (64%) developed some type of opportunistic infection (OI) during chemotherapy or the follow-up, with cytomegalovirus infection being the most frequent OI observed. The median duration of survival from KS diagnosis and from the start of ABVi therapy was 19 months (range, 3.4-88.5 months) and 9.9 months (range, 0.1-42.4 months), respectively. CONCLUSIONS The high rate of OI during ABVi chemotherapy and the follow-up is of concern, although these infections possibly could be due to our patients' low CD4+ lymphocyte counts. However, no toxic death was observed in our patients, suggesting that ABVi could be used in patients with aggressive disease, especially those who were previously untreated.