From February 1992 to November 1993, forty patients with operable breast cancer tumors larger than three centimeters were enrolled in this study of accelerated neo-adjuvant chemotherapy. Thirty-seven patients are evaluable: one patient was excluded from the protocol and two refused to continue treatment after the first cycle. Chemotherapy consisted of three presurgical cycles of CNF [cyclophosphamide at 600 mg/m2, mitoxantrone (Novantrone) at 10 mg/m2 and 5-fluorouracil at 600 mg/m2] administered every 2 weeks, plus G-CSF (5 microg/kg s.c./day on days 7-12). Twenty-six of 37 patients (70%) achieved objective tumor response and were submitted to quadrantectomy. Toxicity was easily manageable. After a median 55-month follow-up (range 48-70), no locoregional recurrences were observed. Distant metastases occurred in 12/37 (32%) patients. The five-year disease-free (DFS) and overall (OS) survival were 58% and 80%, respectively. Accelerated CNF plus G-CSF proved to be a safe and tolerable regimen yielding a good clinical response thereby increasing the possibility of breast conservation surgery for patients otherwise candidates for mastectomy.