The purpose of this prospective trial was to study a combined-modality treatment including local consolidation by surgery or radiotherapy and high-dose chemotherapy (HDC) followed by peripheral-blood stem-cell (PBSC) transplantation. In all, 48 patients with oligometastatic breast cancer amenable to local treatment after induction chemotherapy with epirubicin and cyclophosphamide or paclitaxel and cisplatin, depending on prior adjuvant chemotherapy, were enrolled. The median follow-up was 41 months (range, 7-85 months). PBSC were collected in 47 patients, and 40 received one or two courses of HDC. Local therapy was given in 37 patients. No treatment-related deaths occurred. Of 47 evaluable patients, 36 (75% of intention-to-treat population) had no evidence of disease or complete remission after completion of therapy. Six patients (12.5%) had partial response, two patients (4%) no change, and three patients (6%) progressive disease. The median time to progression and overall survival was 17.5 (95% confidence interval (CI), 14-21 months) and 42.2 months (95% CI, 33-52 months), respectively, and 27% of patients were progression free after 5 years. In conclusion, patients with oligometastatic breast cancer can be treated safely with this combined modality protocol with promising relapse-free survivals.