The role of high-dose chemotherapy (HDCT) in patients with refractory breast cancer is not well established. Forty-two female patients (median age of 46 years) with breast cancer refractory to neoadjuvant chemotherapy received HDCT (cyclophosphamide, carmustine and thiotepa) supported by an autologous peripheral blood stem cells transplant. Their disease had been refractory (defined as less than partial response) to one (18 patients) or two (24 patients) regimens of neoadjuvant chemotherapy. Twenty-nine patients had surgery before HDCT. The best response after surgery, HDCT, and radiation therapy was assessed 60 days after transplantation. Thirty patients had complete remission, eight had a PR, one had a minor response, and three had progressive disease. In seven of 13 patients whose disease was inoperable before HDCT, it became operable. After a median follow-up of 42 months, 21 patients were alive, and 15 remained disease free. Five-year overall survival (OS) was 57% (CI, 50-64%), and the estimated 5-year progression-free survival was 40% (CI, 32-48%). Both OS and PFS were better in patients whose disease became operable after chemotherapy than in those whose disease remained inoperable. A randomized study is warranted in this patient population.