The clinical efficacy of "CMF" chemotherapy, (cyclophosphamide, methotrexate, 5-fluorouracil), was evaluated on advanced and recurrent breast cancer. The response rate was 36.1% in 61 evaluable cases, including four CR and eighteen PR. In terms of efficacy classified by metastatic lesion, the effective rates were 51.4% in soft tissue, 28.6% in viscera, and 20.0% in bone metastases. The main side effects were nausea/vomiting, anorexia, and leucopenia. In this study, CMF chemotherapy resulted in good clinical effects, and its response rate was almost the same as that to CMF chemotherapy in Europe and USA, but slightly lower than that to CAF chemotherapy. As to the side effects, the incidence of leucopenia, thrombocytopenia or alopecia was lower in CMF chemotherapy than in CAF chemotherapy. Also, unlike CAF chemotherapy, CMF chemotherapy had no cumulative dose-limitation and showed no cardiotoxicity. In conclusion, CMF chemotherapy is considered to be one of the most useful treatments for advanced and recurrent breast cancer.