In a retrospective study of 305 patients with primary inoperable cancer of the breast, the over-all survival rate at five years was 12 per cent for those presenting with extensive lesions of the breast alone and 5 to 7 per cent for those with distant metastases. There was little difference in the survival times for any group within the study. Primary inoperable remains a useful classification for predicting prognosis. All survival curves suggested that distant metastases were present when the patients were first seen, whether obvious or not, and early use of combination chemotherapy for all patients is encouraged. Radiation therapy was the most effective treatment in terms of survival times for patients with local lesion. Palliative mastectomy after radiation therapy increased local control but not survival times. The influence of distant metastases on prognosis reflected both the site of metastases and the over-all extent of involvement. Bone metastases did not seem to detract from survival times as much as extensive lesions of the breast did when either of these sites of involvement accompanied other metastases. Outlook was so poor for patients with advanced lesions of the breast plus disease in the pleura and lung or in the liver that the early use of the most effective therapy available is encouraged. Endocrine ablation in these patients with no predictive criteria available was as effective as in those patients with recurrent inoperable cancer and favorable selection factors present.