144 patients with disseminated breast cancer entered into a 4 arm randomized trial. They received a chemotherapy protocol combining monthly administration of adriamycin (40 mg/m2 on day 1), vincristine (1,2 mg/m2 of day 2), cyclophosphamide (400 mg/m2 on days 3, 4, 5), 5 fluorouracil (500 mg/m2 on days 3, 4, 5). Patients in groups I and III were given 6 courses at monthly intervals and patients in groups II and IV were given 10 courses. Then they were given indefinitely a monthly course of cyclophosphamide (100 mg/m2/day for 7 days), melphalan (2,5 mg/m2/day for 7 days), methotrexate (25 mg/m2/week for 3 weeks). Patients in groups III and IV were given 3 applications of living BCG disposed on a scratched area between courses of chemotherapy. The overall response rate was 73 per cent (105/144) and was comparable in each treatment group. The mean duration of response and the mean survival times were comparable in each treatment group. The mean duration of response and the mean survival times were comparable in the 4 treatment arms. The initial tumor mass, serial levels of CEA and skin responses to recall antigens were of prognostic significance. Age, hormonal status, initial lymphocytes count had no prognostic significance.