One hundred patients with tuberculous mastitis were referred to the Tata Memorial Hospital, a cancer center, with a clinical diagnosis of malignancy. This study identifies the possible causes of misdiagnosis and reviews the management of these patients. A lump in the breast with or without ulceration was the commonest presentation, the others being diffuse nodularity and multiple sinuses. Concomitant axillary lymph nodes were found in one-third of the patients. Tuberculosis lesions such as nodular mastitis, disseminated mastitis, and sclerosing lesions clinically mimicked a fibroadenoma, carcinoma, and fibrocystic mastitis depending on the mode of presentation. A young, multiparous, lactating woman with a lesion should arouse the suspicion of tuberculous mastitis, although pretherapeutic pathologic confirmation of a benign disease is mandatory. Mammography, fine-needle aspiration cytology, and excision biopsy for this purpose are successful in 14%, 12%, and 60% of cases, respectively. Acid-fast bacilli were identified in 12% patients. All patients received antituberculous chemotherapy, and 14% patients required simple mastectomy, due to either lack of response to chemotherapy (10%) or large painful, ulcerative lesions involving the entire breast (4%). Axillary dissection was performed in only 8% patients with large ulcerated axillary nodes. All patients, followed for a minimum of 2 years, were free of disease after therapy.