A 58-year-old woman, not having any history of pulmonary tuberculosis, was admitted to our hospital to examine a tender lump in her right breast. A breast echogram disclosed a well-defined hypoechoic mass lesion, indicating a pyogenic breast abscess. The patient underwent incision, drainage and resection of the tumor under local anesthesia. Histological findings of the resected tumor revealed epitheloid cell granulomas with caseous necrosis in mammary glands, suggesting tuberculosis of the breast. After operation, treatment with isoniazid, rifampisin and ethambutol hydrochloride was begun. After one year, she had complete healing without any indication of recurrence. During the last 10 years, 12 cases of tuberculosis of the breast have been reported. Their ages ranged from 28 to 84 years with an average of 42.8 years. Only one cases had a past history of tuberculosis and in the other cases tuberculosis of the breast was considered to be a primary disease. Axillary lymph-nodes involvement and formation of pyogenic breast abscess occurred in each 7 cases. Acid-fast bacilli were demonstrated in 25% of the reported cases. The histological findings of resected specimens and punch biopsy revealed epitheloid cell granulomas with caseous necrosis in 11 of 12 cases. Seven of 11 cases were treated with combination of surgery and antituberculous chemotherapy.