Chemotherapy and chemoimmunotherapy of Stage IV B malignant melanoma were compared in 88 patients. Chemotherapy consisted of DTIC 250 mg/M2 of the body surface area daily x five days and actinomycin-D 2 mg/M2 on day 1 repeated every 3--4 weeks. Chemoimmunotherapy consisted of the same regimen plus C. parvum 2 mg/M2 I.V. daily for 14 days before every third cycle of chemotherapy, plus 2 mg/M2 I.V. daily on days 7 and 14 of each 21--28 day chemotherapy cycle. There was 32 evaluable chemotherapy and 33 evaluable chemoimmunotherapy patients and the groups were well balanced for clinical and pathologic as well as prognostic variables. The complete and partial remission rates, remission and survival durations, and hematologic and gastrointestinal toxicities were different in the two randomized groups being 6 and 3%, 9 and 9%, 7.6 and 12 months, 8.8 and 6.0 months, 20 and 16%, and 62 and 70%, respectively for these parameters. This difference was not statistically significant. Therefore, it can be concluded that the results of chemotherapy with actinomycin-D plus DTIC were not substantially different from those reported using DTIC alone, and that we cannot recommend the addition of actinomycin-D to DTIC for palliative management in these patients. Furthermore, C. parvum immunotherapy did not add to chemotherapy in terms of remission rate, remission duration, or survival for patients with Stage IV B malignant melanoma.