BACKGROUND Classic Kaposi's sarcoma is a rare tumor with an indolent behavior. Local therapy is not applicable in disseminated cutaneous disease. Patients with advanced disease are usually treated with systemic chemotherapy. OBJECTIVE To assess the effectiveness and toxicity of single-agent vinblastine in the treatment of disseminated and recurrent Kaposi's sarcoma. METHODS Ten patients with wide cutaneous spread of classic Kaposi's sarcoma were treated with single-agent vinblastine, 6 mg/m2 intravenously once every 2 weeks. Vinblastine was continued for 2 months after achieving a maximal response. RESULTS The male:female ratio was 2.3:1, and median age 64 years (range 50-79 years). The median number of involved nodules in the skin was 34. The overall response rate was 90%, 5 with complete response (50%) and 4 with partial response (40%). Complete responders had a longer duration of response than partial responders: 41.2 vs. 14.8 months. The median survival of all patients was 33 months. Side effects were minimal and tolerable. CONCLUSIONS Vinblastine is very effective in the treatment of extensive classic 'Kaposi's sarcoma, and results in a high response rate, long survival and disease-free survival with tolerable toxicity.