This study compares hearing results after stapedotomy by 0.6 mm and 0.8 mm teflon pistons. Retrospective analysis studied 100 patients randomly selected who underwent stapedotomy for otosclerosis with insertion of 0.8 mm teflon piston prosthesis and 100 patients with 0.6 mm teflon piston prosthesis. Air-conduction hearing level in both groups were measured before and after the procedure and the gain of the air conduction between the 2 groups at different frequencies were compared statistically. The group with the 0.8 mm prosthesis had better results that were statistically significant and more pronounced at lower frequencies.