Summary An eighteen year survey of thirty-six cases of cancer of the breast occurring in young Negro patients (thirty-five years or younger) is presented. All patients were female. The youngest patient, fifteen years of age, died of generalized metastases two years after radical mastectomy. Fifty-six per cent occurred in nonparous patients. The most common symptom was a painless mass and the upper outer quadrant was most commonly involved. There was one case of bilateral metachronous involvement and none of synchronous involvement. Postoperative x-ray treatment and prophylactic castration were of doubtful value, while therapeutic castration was of definite benefit. Testosterone and cortisone produced minimal beneficial result. On the basis of total experience, our five year clinical cure rate was 39 per cent. The five year cure rate with positive nodes was 23 per cent and with negative nodes it was 78 per cent. These figures compare favorably with those in our older patients. All four patients with cancer developing during pregnancy and lactation died of the disease. However, they all had positive axillary nodes. Nevertheless, we still believe radical mastectomy to be the treatment of choice for operable breast cancer appearing during pregnancy and lactation. There were no five year survivals in patients below thirty years of age with positive axillary nodes. Thus, the single most important factor affecting five year survival in our series was the absence or presence of axillary metastases. On the basis of our limited experience, the thesis that cancer of the breast in young women has a uniformly poor prognosis is not tenable.