Between June 1989 and June 1992, 12 patients with advanced multiple myeloma underwent peripheral blood stem cell autotransplantation after high-dose chemotherapy and radiotherapy. The conditioning regimen included melphalan (140 mg/m2), high-dose cyclophosphamide (120 mg/kg), methylprednisolone (2 g daily x 7), and total body irradiation (9-12 Gy). Transplant morbidity included severe mucositis (n = 7) and acute renal failure (n = 2) related to infusion of the stem cells. Engraftment was delayed (n = 4) in this heavily pretreated population, and two patients had complete graft failure. Despite the advanced nature and chemotherapy-refractory state of their disease, 11 of 11 evaluable patients achieved an objective response. Six patients survived to leave the hospital, and four remain alive--one died of acute leukemia induced by prior melphalan exposure. Three of the four are relapse-free at a median of 24.9 months (range, 18-28 months). Some patients with advanced refractory multiple myeloma can achieve objective responses from highdose chemoradiotherapy with peripheral blood stem cell rescue. Harvesting peripheral blood stem cells from high-risk patients early in their disease for later use may decrease the risk of graft failure. Peripheral blood stem cell transplantation after high-dose chemotherapy and total body irradiation can produce durable responses in patients with advanced refractory myeloma.