Advanced AIDS-associated Kaposi's sarcoma often requires systemic cytotoxic chemotherapy. Despite high response rates, the majority of the patients die of opportunistic infections (OIs). Effective anti-retroviral agents in combination with cytotoxic chemotherapy may be useful in preventing the development of OIs in addition to increasing the tumor response. Twelve patients with extensive EKS were treated with a non-myelosuppressive drug regimen consisting of bleomycin and vincristine (BV) in combination with the anti-retroviral agent, zidovudine (ZDV). The dose of ZDV was 200 mg orally every four hours (full dose) in eight patients (Group I) or 100 mg orally every four hours (half dose) in four patients (Group II). Toxicity was acceptable with only 3 patients (all from Group I) requiring blood transfusions. ZDV dose reduction due to granulocytopenia was required in 6 patients (5 in Group I and 1 in Group II). Only two patients developed OIs during 27.5 cumulative months of therapy. The overall response rate was 83% in both groups with 4 patients achieving complete remission (CR) and 6 patients acheiving a partial remission (PR). We conclude that a combination of (BV) chemotherapy and ZDV can be used safely with high response rates. Prospective studies of such combination regimens are currently in progress.