Objective: This study aimed to evaluate the benefits of cochlear implant (CI) on speech perception, quality of life (QoL), and cognitive function in profoundly deafened older adults.Design: Longitudinal and cross-sectional cohort study.Study sample: Participants in this study were CI recipients aged 65 years or older (experimental group), CI recipients aged 50 years or younger (control group 1), and normal-hearing participants aged 65 years or older (control group 2).Results: Speech perception significantly improved in both groups of implanted patients (preoperative vs. 1-year median [IQR] sentence recognition: older patients, 0 (0-20) vs. 90 (70-95), p = 0.001; younger patients, 35 (0-50) vs. 90 (80-100), p = 0.001). There were no significant differences in QoL (Glasgow Benefit Inventory) between younger and older patients (median [IQR] overall benefit score, 42 (31-64) vs. 53 (39-69), p = 0.2). Mini-Mental State Examination scores showed no significant differences between elderly CI recipients and normal-hearing participants (median [IQR], 28 (26-28) vs. 28 (27-29), p = 0.5).Conclusions: Cochlear implantation rehabilitation allows the profoundly deafened older adult to lead a QoL comparable to that of a younger patient. The correlation between hearing restoration and cognitive function preservation in older adults suggest a possible role for CI as a useful resource in limiting age-related cognitive decline.