A 4 years old girl came in the hospital on July 31, 1967, having the preoperative diagnosis of the left chronic suppurative otitis media with retroauricular fistula. When the mastoid was operated on Aug. 2, 1967, it showed extensive irregular bony destruction and filled with easily bleeding granulation. Tuberculous bacilus could not be approved by smear and culture, but histological study showed tuberculous finding. Antituberculous agents were postoperatively administrated and the operated wound showed dryness within 1, 1/2 months. This case was diagnoed as so called primary tuberculosis of the middle ear after operation.