Twenty-three patients with advanced melanoma were treated with a combination of subcutaneous recombinant human interleukin-2 (IL-2), and recombinant interferon alpha-2a (IFN-alpha) with chemotherapy consisting of four cycles of carboplatin (300 mg/m2, day 1) and vinblastine (6 mg/m2, day 1), every 28 days (CV-IL-IF). IL-2 was given at a dose of 4.5 x 10(6) U twice daily on days 3-6 and days 21-24 of each cycle; IFN-alpha dose was 4.5 x 10(6) U, starting on day 2, thrice weekly. Immunotherapy was intended to continue for 6 months. Of the 23 analyzed patients, 4 (17%) achieved an objective response, including 1 complete and 3 partial responses, in nonvisceral metastatic disease. The median time to progression was 5 months and the median survival from onset of the treatment 6 months (range 1-14 months). Four patients discontinued the treatment, due to nonhaematologic toxicity; 3 for severe weakness and the 4th patient for long-lasting CNS side-effects. Other grade 3-4 toxicities included weight loss (22%), nausea and vomiting (17%) and alopecia (13%). The haematologic toxicity was acceptable. No toxic death was noted. It is concluded that the CV-IL-IF regimen has limited activity and moderate toxicity.