The benefits of cochlear implantation (CI) in the elderly remain debatable in terms of sound and speech perception. Moreover, the results of CI may be affected by the intensity and pitch of spoken language. We conducted a retrospective study to evaluate surgical and hospitalization times, postoperative complications, and hearing outcomes after CI in elderly Koreans. Our study population was made up of 55 postlingually deafened adults who underwent unilateral CI. They were divided into two groups based on age; an older group consisted of 21 patients aged 65 years or older (mean 71.8) at the time of CI, and a comparison group was made up of 34 patients aged 18 to 64 years (mean: 47.5). The mean surgical and hospitalization times and the mean number of postoperative complications in the two groups were comparable. Auditory outcomes were quantified by the speech reception threshold (SRT), the speech discrimination test (SDT), scores on the Korean version of the Glendonald Auditory Screening Procedure (GASP-K), and categories of auditory performance (CAP) scores. The SDT and GASP-K values were significantly lower in the older group at 3 months, 1 year, and 2 years; there were no significant differences in mean SRT and CAP values. We conclude that elderly patients may obtain appreciable benefits from CI without experiencing serious surgical complications. Nevertheless, difficulties in speech perception should be taken into consideration in older patients.