Fifty-two previously untreated patients with multiple myeloma were randomized to either a combination of recombinant interferon (rIFN) alpha-2 and chemotherapy or chemotherapy alone. Patients were treated with vincristine, melphalan, cyclophosphamide and prednisolone every 4-6 weeks. In the combined treatment arm rIFN was administered concurrently with chemotherapy as well as during chemotherapy free intervals. The combined regimen effected 17/21 (80.9%) responses as compared to 19/27 (70.4%) responses in VMCP treated patients. Addition of rIFN to chemotherapy did not enhance hematologic toxicity. These findings suggest a somewhat higher rate of objective response in the VPMC + rIFN group, although a significant improvement in median survival by adding rIFN to conventional first line polychemotherapy in myeloma patients has not yet been achieved.