127 breast scans were performed on 83 female patients using technetium-99m diphosphonate. 46 out of 48 patients with breast cancer had positive breast scans manifested by a focal increased uptake in 37 patients and a diffuse increased uptake in the remaining 9 patients. Benign breast lesions such as fibrocystic disease, fibroadenoma and fat necrosis may also concentrate the radioactive agent in a focal or a diffuse pattern. So breast scanning is a sensitive though nonspecific modality to detect malignant breast lesions and it is worthwhile performing it on all women referred for bone scan.