Objective: To analyse the cost-effectiveness of unilateral cochlear implant (CI) surgery in Italian adults with post-lingual deafness, focusing on direct costs, Health Utilities Index (HUI), Quality-Adjusted Life Years (QALY), and Incremental Cost-Effectiveness Ratio (ICER). Methods: The analysis, from the Italian healthcare system perspective, included preoperative, surgical, hospitalisation, and postoperative costs. QALYs were estimated using the Italian Nijmegen Cochlear Implant Questionnaire (I-NCIQ) and Ontario Health Utilities Index Mark 3 (HUI-3). HUI-3 score changes were analysed with regression models in Stat View (v5.0.1, SAS Institute Inc). ICER was calculated as the incremental cost per QALY (in Euros/QALY) over the average patient's lifetime. Results: CI significantly improved I-NCIQ (p < 0.001) and HUI-3 scores (p < 0.0001). Average life expectancy at surgery was 21.2 years; the degrade factor was 0.97, yielding a lifetime gain of 2.717 QALYs. Direct costs amount to €19,467.65. Cost-utility analysis showed €7,165.13 per QALY, below the €30,000/QALY ICER threshold. Conclusions: CI surgery is cost-effective based on QALY analysis. Although cost-effectiveness decreases with age, quality of life and health benefits are comparable to younger patients.