<p>Indications for cochlear implantation (CI) are constantly expanding beyond severe and profound deafness to include patients with unilateral deafness and, more recently, congenital anatomical malformations of the inner ear [Karamert et al., 2022]. Among congenital cases of sensorineural hearing loss, developmental inner ear malformations (IEM) account for approximately 20% of cases, with up to 35% meeting the criteria for cochlear implantation [Sennaroglu et al., 2010, 2017]. Increasing use of magnetic resonance imaging (MRI) and computed tomography (CT) scanning of the temporal bone has led to expansion of the population of cochlear implant recipients among patients with IEM, and this naturally requires retrospective evaluation of clinical outcomes. There is clear importance in evaluating not only surgical results, which primarily characterize the safety of CI in this subgroup of patients, but also audiological outcomes: the extent of recovery of speech and auditory perception, without which it is not possible to get a complete picture of the efficacy of cochlear implantation. Given the diverse anatomy of the cochlea in IEM, determination of the type of electrode array, its length and insertion depth, and selection between CI or brainstem implantation are of paramount importance when planning cochlear implantation, not only for the success of the surgical intervention itself, but also for the results of subsequent auditory and speech rehabilitation. The objective of this review is to analyze data in the current literature on assessment of the audiological results of cochlear implantation in patients with congenital IEM as compared with patients with normal cochlear anatomy. We sought to identify IEM types in which CI gives the best results, as well as those malformations which require careful planning of the surgical stage, a specific choice of electrode array, and prevention of possible postoperative complications.</p>