Congenital deafness plays a special part in the present-day otorhinolaryngology, its importance is globally recognized. In the recent years, medicine has greatly succeeded in the treatment and rehabilitation of patients born deaf. However, even such advanced surgical and rehabilitation methods as cochlear implantation performed in early childhood, in some situations, does not make it possible to achieve optimal results of oral speech, psychological, social rehabilitation of patients, to meet all their requirements and expectations. The heterogeneity of the results is explained by the etiological diversity of congenital deafness. According to our foreign colleagues, infectious and genetic factors are the most significant in the etiology of congenital deafness. However, in our country there is no reliable information about etiological profile of the patients born deaf who seek cochlear implantation. In July 2018, a study of congenital deafness etiology in the candidates for cochlear implantation of toddlers was started in the premises of Saint Petersburg Research Institute of Ear, Throat, Nose and Speech. In this article, we present the first results of our etiological search.