One hundred and five patients with metastatic breast cancer were treated with 5-fluorouracil, Adriamycin, cyclophosphamide and BCG (FAC-BCG). The results were compared to those observed in a group of 44 patients treated with FAC chemotherapy alone. Although the overall response rates were similar (76% for FAC-BCG and 73% for FAC), the duration of remission was of 9 months for FAC and 14 months for FAC-BCG (p = 0.04). Similarly, survival or responding patients treated with FAC-BCG was significantly longer (24 months) than that observed in the chemotherapy alone treated group (15 months). There was no difference in survival or duration on study for non-responders. Response rates were not influenced by dominant site of disease, menopausal status or disease-free interval. The duration of remission and survival, however, were significantly longer for patients with bone and soft tissue involvement than for patients with visceral metastasis. Similarly patients with 1 or 2 metastatic sites survived significantly longer than those with more than 3 organ sites involved (p = 0.02). This chemotherapeutic combination is highly effective in inducing remissions. In addition, nonspecific immunotherapy with BCG appears to prolong duration of remission and survival for responding patients.