The bone scan has become a major staging and screening test for patients with carcinoma of the breast. The routine use preoperatively of bone scans to detect occult osseous metastases has been advocated to prevent radical operations on patients with Stage IV disease. Periodic use post-operatively of bone scans has also been advocated to detect metastic disease before the onset of symptoms. In view of the prevalence of this disease, the implications of this approach in terms of cost alone warrant consideration. All bone scans obtained of patients with carcinoma of the breast during a five year period were reviewed and the results correlated with the pathologic stage of the disease, the presence or absence of symptoms and pertinent clinical data. The sensitivity, specificity and predictive value of the bond scan was then analyzed for each group. Recommendations for the use of bone scans in patients with carcinoma of the breast are based upon these data.