Breast hamartoma is an uncommon benign tumor rarely associated with malignancy. An excision and histological examination is necessary for the differential diagnosis. We report a case of a 49-year-old female patient presenting with a lump in the right breast. Ultrasound examination which demonstrated a 4.4*1.1 cm hypoechoic lesion with lipoma. Partial mas-tectomy was arranged and the diagnosis of a hamartoma was confirmed by the histological examination.