We describe the results of a clinical trial to evaluate the feasibility and toxicity of autologous hematopoietic stem cell transplantation (auto-HSCT) for patients with progressive multiple sclerosis (MS). Fifteen patients (all patients with secondary progressive MS) were enrolled. The median expanded disability status scale (EDSS) score at baseline was 6.0 (range, 4.5-7.5). Peripheral blood stem cells were obtained by leukapheresis after mobilization with granulocyte colony-stimulating factor. In 9 patients, CD34(+) cell selection was performed with a CliniMACS cell selection system, and 6 patients accepted infusion of unmodified peripheral blood stem cells. The modified BEAM (carmustine, teniposide, cytarabine, and melphalan) was the sole conditioning regimen used. The adverse effects included infections, mucositis, transient hepatotoxicity, and diarrhea. Three patients had flares of neurologic deterioration during mobilization, 8 patients had the same manifestation during transplantation, and 2 patients had similar flares within 3 months of transplantation. Six patients experienced continuous neurologic improvement after transplantation, 5 patients experienced neurologic progression, and 4 patients had stabilization of their disease. The confirmed progression-free rate was 63.8% at 49 months. The results of lymphocyte purging were no better than for no purging. Auto-HSCT proved to be safe and beneficial for some MS patients. Further studies are needed to establish the merit of this procedure for MS patients.