Postmenopausal patients (51) with advanced breast cancer were randomized to receive cyclophosphamide given continuously or cyclophosphamide given continuously with methotrexate, 5-fluorouracil, vincristine and prednisone given intermittently. The results with multiple drug therapy were significantly better than with single drug therapy, with regard to percentage (63 vs. 25%) and median duration (100 vs. 210 days) of objective response. Toxicity was moderately increased with combination as compared to single drug treatment.