More than in 10% of breast cancer patients distant metastases are detected at diagnosis. The results of treatment of 191 patients are presented. Removal of the primary tumor in case of newly diagnosed advanced breast cancer (oligometastatic) increases the mean duration of life from 26 months up to 38 months (p < 0.01). 3-year overall survival increases from 49% to 71% (p = 0.001), and a 5-year survival-from 18% to 47% (p = 0.001). 9% of patients with metastatic breast cancer who underwent mastectomy live 10 years and more. The relative risk of death in the presence of distant metastases after resection of primary tumor, on average decreases by 34%. By means of multivariable analysis the best results after mastectomy were obtained in the localization of distant metastases in the bones and soft tissues, high expression of steroid hormone receptors, the absence of overexpression of HER2/neu, luminal A type, positive response to preoperative systemic therapy and attaining free surgical margins.