Although high-dose therapy (HDT) with autologous hematopoietic stem cell transplantation (ASCT) is widely accepted as an effective and safe consolidation therapy for multiple myeloma (MM), few reports on its efficacy are available in Korea. We present the results of a prospective phase II study, involving 33 patients with MM treated with HDT with ASCT. The treatment consisted of 4 courses of VAD (vincristine, adriamycin, dexamethasone) induction, peripheral blood stem cell collection, and high-dose melphalan with stem cell infusion. The overall response rate was 93%, with 45% of patients having complete responses. The toxicity was predictable and tolerable. With a median follow-up of 27.6 months, the 2-year event free survival rate was 43%. At the time of writing, the median overall survival duration had not been reached with 2-year survival and projected 3-year survival rates of 81% and 74%, respectively. The overall survival was significantly better than that of the historical control patients (N=82) treated with conventional chemotherapy at our institution. The results suggest that HDT with ASCT is a valuable first or second-line treatment for patients with MM.