Aim: Cochlear implants (CIs) aid in language and speech development through improved hearing in patients with bilateral severe or profound hearing loss. In this study, we evaluated the outcomes of our patients undergoing CI surgery. Materials and Methods: Preoperative, perioperative and postoperative clinical and audiological findings, hearing loss etiology, surgical approach techniques, and complications were evaluated retrospectively in 31 patients (35 ears) undergoing CI surgery. Results: Thirty one patients (13 adults and 18 children) were included in the study. After posterior tympanotomy following cortical mastoidectomy, electrodes were introduced through the round window in 21 ears and via cochleostomy in 14 ears. CIs with different number of electrodes (22, 16, 12) from 3 different companies were used. No postoperative complications were observed in any of the patients. The mean free field audiogram (FFA) was 95.2±19.13 dB preoperatively and 37.8±8.46 dB postoperatively in 24 patients who attended the control visits. Postoperative hearing gains were significantly different from the preoperative values (p<0.001). There was no significant difference between different devices (p=0.340). Electrodes were introduced through the round window or by cochleostomy, and comparison of these two groups revealed no statistically significant difference in terms of postoperative FFA values (p=0.425) or speech awareness threshold and speech reception threshold values (p=0.132). Conclusion: The significant hearing gains in the postoperative period without any complications indicate the success of the surgical technique utilized in this study. It can be said that the difference in electrode insertion location and numbers does not affect the postoperative results.