This study was designed to determine the complete response (CR) rate, event-free survival (EFS) and overall survival (OS) in patients with metastatic breast cancer treated with an adriamycin-based induction regimen, high-dose chemotherapy consisting of cyclophosphamide and thiotepa with autologous bone marrow or stem cell reinfusion, followed by post-transplant 5-fluorouracil and cisplatin. Forty-eight consecutive patients were enrolled and 35 received two to four cycles of a cytoreductive chemotherapy regimen followed by high-dose chemotherapy which included cyclophosphamide and thiotepa. Thirty-three patients with non-progressive disease received at least one cycle of post-transplant 5-fluorouracil and cisplatin. Fifty percent of patients with evaluable disease responded to induction chemotherapy. Three of the 34 patients (9%) evaluable for response to high-dose chemotherapy achieved CR, eight (24%) achieved partial response (PR), 12 (35%) had stable disease (SD) and 11 (32%) had progressive disease (PD). The median time to neutrophil recovery was 11.5 days (range, 8 to 40 days) post- reinfusion. The median time to platelet independence was 14.5 days (range, 8 to 44 days). The median follow-up is 24.5 months (range, 1 to 96 months). The actuarial probability of EFS for all patients is 17% at 4 years. The EFS for patients receiving all four cycles of post-transplant chemotherapy is 27% at 4 years, compared to 36% at 1 year for patients not receiving any post-transplant chemotherapy. Ten of the 48 patients (21%) are alive, and seven of these (15%) have no evidence of disease. High-dose chemotherapy with autologous bone marrow or peripheral blood-derived stem cell transplantation followed by post-transplant consolidation chemotherapy in patients with metastatic breast cancer results in a proportion of patients without evidence of disease at 4 years.