This study was carried out to evaluate the anatomical and hearing results of the reparation of attic defects in closed tympanoplasty. Reparation was carried out in 194 patients by using a costal cartilage allograft, and in 159 patients with a bone pate autograft. The follow-up was from 1 to 5 years. The study was not truly randomized owing to an occasional lack of allogenic costal cartilage. In the group 'costal cartilage' a partial resorption was observed in 5.7% and a complete resorption in 4.7% of the cases. In the group 'bone pate', partial resorption was observed in 5.5% and total resorption in 2.7% of the patients. Satisfactory hearing results were obtained in 86% of the patients of the group 'costal cartilage' and in 82% of the patients of the group 'bone paté'. Both graft materials may be recommended for repairing erosions caused by the cholesteatoma in the wall of the external auditory canal.