In 515 patients with primary carcinoma of the breast T1a-3aN1a-bM0, the authors conducted simple mastectomy with radical lymphonodectomy of the axilla from 1976 onwards to the time of reporting. In 190 patients with affected lymph nodes, assisting chemotherapy was effected with a combination of three drugs, namely, trofosfamide, methotrexate and 5-fluoro-uracil for a period of 12 months postoperatively. Patients whose lymph nodes remained free were not subjected to follow-up treatment. For both groups of patients, the rates of relapses and survival times were established for an average follow-up time of 41 months (15-75). No significant differences in the rates of relapses and localisation were seen on comparing both groups (P = 0.27). In the patients with affected lymph nodes, local relapses were somewhat more frequent than with patients whose lymph nodes were not affected (11.1% vs. 9.8%); the same also applied to the occurrence of metastases distant from the primary tumour (12.1% vs. 7.4%). Significant differences in survival rates in patients with affected lymph nodes were seen only in the tumour stages T1/T2 (P = 0.001) and for the stages T2/T3 (P = 0.009). The menopausal status of the patients did not show any significant differences in respect of probability of survival for both groups (N-:P = 0.75; N+:P = 0.79).