One hundred twenty pathologically confirmed operable Stage III (T3N0-2) breast cancer patients were randomized to receive either postoperative radiotherapy or chemotherapy, or a combination of these, with or without levamisole immunotherapy. Radiotherapy was given to regional lymph node areas and chest wall. Chemotherapy consisted of 6 cycles of Adriamycin (doxorubicin) (45 mg/m2), vincristine (1.2 mg/m2) intravenously, and cyclophosphamide (200 mg/m2 for 5 days) perorally every 4 weeks. Peroral levamisole, 150 mg a day, 2 days weekly, was given as an immunotherapy. The 3-year results are described in this article. The effect of levamisole on the prognosis cannot be evaluated yet because of the short follow-up period. The disease-free survival was almost equal in each patient group, however, some benefit was achieved by levamisole (a shift of disease-free survival from 12 to 18 months). The patients receiving radiotherapy alone had the poorest prognosis: 68% had a recurrent tumor, and 57% were alive. In the chemotherapy group, the figures were 53% and 72%, respectively. Patients who received a combined treatment had the best prognosis: 13% had a recurrent tumor, and 90% survived 3 years. There was a statistically significant difference in the recurrence rate between any single therapy and the combined treatment (radiotherapy to combined treatment, P less than 0.001, chemotherapy to combined treatment, P less than or equal to 0.01 chi-square test). In overall survival, a statistically significant difference was reached between radiotherapy and combination treatment groups (P less than 0.01, chi-square test). Radiotherapy gave a good local control of the tumor, and chemotherapy decreased the number of metastases. The nonmetastatic axillary lymph node status and secondary amenorrhea or severe menstrual disturbances were of positive prognostic value. The side effects due to radiotherapy and chemotherapy were moderate and tolerable. The dose of Adriamycin had to be reduced only in four patients. All of the patients receiving chemotherapy had a transient total alopecia. Three of them had nonlethal arrhythmias, and one had skin rash. Levamisole was found very toxic with 9 cases of transient agranulocytosis, leading to the discontinuation of immunotherapy in 22 of 59 patients. Our results show that radiotherapy controls the tumor only locally and chemotherapy systematically, but the best patient-saving results are achieved with a combination of radiotherapy and chemotherapy. The disease-free and overall survival are statistically significant, and favor the combined therapy.