Fifty-two patients with progressive resistant multiple myeloma were entered in this Southwest Oncology Group Phase II study, using weekly intravenous Aclacinomycin A. Of forty-three evaluable patients for response, there was one partial remission of 2 years duration and two sustained clinical improvements with 25% reduction in paraprotein. Major toxicity seen was severe myelosuppression and significant nausea and vomiting requiring dose reduction and delay of the scheduled treatment. Cardiac arrhythmia was seen in one patient. Chronic daily schedule or continuous IV infusion is recommended for future study.