The efficacy and toxicity of doxorubicin, bleomycin and vindesine in epidemic Kaposi's sarcoma, and the role of rh GM-CSF in chemotherapy-induced neutropenia were evaluated in this Phase II study. Patients with progressive Kaposi's sarcoma were eligible, and were staged according to ACTG criteria. Treatment consisted of 20 mg/m2 doxorubicin, and a fixed dose of 15 mg bleomycin and 4 mg vindesine every 2 weeks. All patients continued antiretroviral medication with severe myelosuppression, patients received subcutaneous 5 μg/kg rh GM-CSF (Leucomax) from days 2-12. Response and toxicity were measured according to ACTG and WHO criteria. 27 patients were evaluable, 25 patients classified as having a poor prognosis. The response rate was 70% (3 CR, 16 PR), the duration of response was 18 weeks (range 8-25) and the median survival 30 weeks (range 4-63+). The cause of death was mostly opportunistic infection. 4 patients died of pulmonary Kaposi's sarcoma. The toxicity of this regimen was mainly myelosuppression and 13 patients were treated with rh GM-CSF. Complete recovery of the white blood cells occurred in seven of the 27 courses of rh GM-CSF (26%). No bacterial infections were recorded, but 5 patients (19%) developed an opportunistic infection during treatment. Peripheral neuropathy occurred in 16% of patients. Combination chemotherapy is effective in poor prognosis Kaposi's sarcoma but has a shortlasting effect. The main toxicity of this treatment is severe myelosuppression which can be ameliorated by rh GM-CSF. It remains to be established whether rh GM-CSF is also able to reduce the incidence of opportunistic infections.