Objective : To determine the quality of life and cost consequences for deaf adults who received a cochlear implant. Methods : The data from 11 patients, post-lingual deaf adults who received cochlear implants from 1990 to 2002, underwent cost-utility analysis. The average age of the participants was 49.6 years. The main outcomes were direct cost per quality-adjusted life-year (QALY) using the visual analog scale (VAS), health utility index (HUI), EuroQol (EQ-5D), and quality well-being (QWB), with costs and utilities being discounted 3% annually. Results : Recipients had an average of 5.6 years of implant use. Mean VAS scores increased by 0.33, from 0.27 before implantation to 0.60 at survey. HUI scores increased by 0.36, from 0.29 to 0.65, EQ-5D scores increased by 0.26, from 0.52 to 0.78, and QWB scores increased by 0.16, from 0.45 to 0.61. Discounted direct costs were $22,320, yielding $19,223/QALY using VAS, $17,387/QALY using HUI, $24,604/QALY using EQ-5D, and $40,474/QALY using QWB. Cost-utility ratios using VAS, HUI, and EQ-5D were all below $25,000 per QALY, except using QWB. Conclusion : Cochlear implants in post-lingual deaf adult have a positive effect on quality of life at reasonable direct costs and appear to produce a net saving to society.