Tuberculosis of the breast has become a rare disease since the advent of antituberculous chemotherapy. The incidence of tuberculous mastitis at Vanderbilt Hospital for the last two decades was 0.025% of surgically treated breast disease. This probably reflects its prevalence in economically developed parts of the world. The pathologic diagnosis of mammary tuberculosis may be difficult. The only diagnostic proof is the demonstration of tubercle bacilli by microscopic smear of culture. Numerous cases have been incorrectly reported as mammary tuberculosis because of nonadherence to this criterion. Definite guidelines for treating breast tuberculosis are not available and may never become so because of its rarity. Drug therapy has been successful and should be tried in all cases. Adequate surgical removal is inevitably corrective of the local disease. Surgically treated patients should receive antituberculous drugs before and after their operations.