Thirty-nine patients with metastatic breast cancer were treated with 3M as first line chemotherapy, the combination of mitomycin-C (7 mg/ m2, day 1) mitoxantrone (7mg/m2, day 1 + 22), and methotrexate (30 mg/m2, day 1+22) in intervals of six weeks. The overall response rate (CR + PR) was 50%; 26% of the patients achieved remission already after the first cycle. Toxicity was remarkably low. Severe alopecia occurred in only 8% of the patients. There was only mild nausea. Significant leukopenia was observed in 4%.