Since spoken language is acquired by listening to the speech, the main consequence of congenital or early acquired hearing loss is a relatively low level of language competence. Therefore, for children with congenital or early acquired hearing loss habilitation of communication is always indicated. Over the past decade, the professional community has accepted opinion that the best outcomes in terms of communication competences and levelling up communication skills with the child's peers are achieved by investing maximum professional efforts to the early detection of hearing impairment. Afterwars, it is of great importance to get hearing aids or cochlear implant as early as possible, intensify listening and speech development, and also to acquire sign language at the same time. This process requires a special, encouraging environment, which includes a multidisciplinary team of experts who intensively prepare the child's family to stimulate the development of communication, hearing, speech and language skills. The aim of this paper is to monitor the effect of bimodal habilitation on increasing the vocabulary of a child with congenital deafness, who uses CI. The purpose of its realization is to inspect the potential of a bimodal approach to compensate for constraints in auditory input and accidental learning that interferes with the enhancement of the vocabulary. The boy did not pass the neonatal screening, and had implanted at the age of 2. The work with the boy, who was 4 years and 8 months old at the beginning of the research, was organized in individual sessions twice a week at the Rehabilitation Center of the Faculty of Education and Rehabilitation in the period from February to June of the current year. During this period the team worked on the improvement of the boy's social communication, hearing, language and speech skills, and the development of early writing skills and fine motor skills. The boy was encouraged by two modalities (speech and manual signs), and in that period the parents were urged to apply the boy's learned communication strategies at home. The progress in the boy's expressive and receptive vocabulary was monitored in several equidistant time points via the Communication Development Inventories II (Koralje). The results of these studies are in line with earlier reports in which the increase in the receptive and expressive vocabulary of children with hearing impairment, CI users, is caused by a logopedic intervention using bimodal approach. Therefore, supplementing the language input with another modality seems to be a good choice for pediatric users whose vocabulary development does not progress at the desired rate