Introduction. One of the few ways to rehabilitate profound hearing loss in elderly patients is cochlear implantation. A number of studies have been published assessing the effect of unilateral cochlear implantation on cognitive function in elderly patients, but the results have been mixed.Aim. Evaluation of the impact of unilateral cochlear implantation on auditory and non-auditory functions in elderly patients.Materials and methods. The study included 50 elderly and senile patients (mean age 67.16 ± 3.5 years). RBANS-H, HI-MoCA tests were used to assess cognitive function. Quality of life, depression and anxiety levels were assessed by HADS, SF-36. Auditory function was assessed by pure tone audiometry, speech audiometry, SSQ, HISQUI19.Results. The study showed improvement in cognitive function in patients with and without residual hearing. There was also an improvement in quality of life, a decrease in depression and anxiety in both study groups. When assessing the auditory function, statistically significant differences between the study groups remained during the study for the sound quality indicator (SSQ test), while other parameters did not have a statistically significant difference at the end of the study. In addition, the study did not reveal a statistically significant effect of vestibular dysfunction on cognitive function in patients.Conclusions. Unilateral CI as a method of rehabilitation of profound impairments of auditory function in elderly and senile patients has demonstrated its high effectiveness.