Objective: Descript and ascess the cochleostomy technique results. Method: Descriptive case study. 52 patients had cochlear implant with the antero-inferior round window niche cochleostomy technique, 2 patients have cochlear deformities who were implanted the straight electrode. Results and Discussion: The antero-inferior round window niche cochleostomy technique has the 100 percent result (in 52 patients). The electrodes are completely inside cochlear with 24 channels which have nervous reflex and accurate scala tympany (low impedance), no complications. Conclusions: Cochleostomy is the most important step. Round window niche is chiefly anatomy landmark The antero-inferior round window niche cochleostomy technique was done successfully in 100 percent of cases. The electrodes were completely inside cochlear. In cochlear deformity, it was checked carefully on CT Scan in order to get the appropriate cochlear implantation. This technique makes sure the exact scala tympany implantation without cochlear damage.