The authors describe their experience concerning collagen implantation in case of glottic insufficiency after cordectomy by the CO2 Laser. Three different kinds of injection are indicated as follows: injection of 3/4 of collagen in the site responding to vocal fold removal on 1/4 in the survival fold after cordectomy with conservation of the thyroarytenoid muscle; implantation of 1/2 in the new fold and 1/2 in the surviving one after cordectomy with removing of the cricoarytenoid muscle; infiltration of the whole material in the residual vocal fold after cordectomy enlarged to the false vocal fold and the ventricule as well. Video laryngoscopic and spectrographic examinations documented good phonatory results after collagen implantation in 19 cases over 21; two cases had a persisting insufficiency depending on the fact they had been previously operated of enlarged cordectomy and the scar tissue was not sufficient for measures and consistency to obtain a satisfactory injection of collagen.