The authors report 1279 surgical operations of otosclerosis performed between 1980 and 1992 in 959 operated patients. They chose the autegenous vein or perichondrium interposition TeflonR piston; however this technique has improved over the past few years. The size of the stapedectomy has been diminishing; from total, then partial stapedectomy, at last to 0.8 mm across stapedotomy. The graft has become exclusively from venous origin and the diameter of the piston has been reduced from 0.8 to 0.6 then to 0.4 mm. Seven groups of patients have been examined according to the size of the incision for stapedotomy or stapedectomy and the size of the piston. The audiometric study was realized after one month, one year, three years, fine or even ten years after surgery. Comparative tests were made considering the sex and the age of the patient, the thinness of the graft, and surgical revisions. The audiometric study lied not only upon the audiometric Rinne's closing but also upon the bone conduction variation (postoperative bc-preoperative bc) in the course of time. The evolution of tinnitus, of vertigo has been, as well, the subject of a careful study in time according to the surgical techniques. The study shows that the audiometric results (Rinne's closing, bc evolution) are statically much better with total stapedectomy, then with partial stapedectomy, at last with stapedotomy in the first three postoperative years. The best audiometric results are obtained with wider pistons (0.8 mm diameter) and venous approach. The results regarding tinnitus and vertigos are dissimilar especially during the first operative year. After three years of evolution, the significant audiometric differences tend to reduce and the audiometric results become the same (no significant difference) whatever the surgical technique may be. After three years, simple, calibrated stapedotomy without interposition statically gives similar results in literature. However, each surgical technique may, though rather infrequently, produce some incidents or complications that undoubtedly influence the operator as for the choice of the surgical technique to use.