The benefit of cochlear implants in the mtreatent of profound bilateral sensorineural hearing loss is undeniable. In Switzerland, bilateral cochlear implantation is the treatment of choice in bilateral deafness in children. Due to the anatomical relations of the cochlea and the vestibule, vestibular function can be affected during implantation. Bilateral vestibular areflexia can significantly impair the quality of life and a child's development. Therefore, even if the theoretical risk of bilateral vestibular arefilxia after cochlear implantation is only about 1%, it must be taken into account. Vestibular function assessment must be part of the pre-implantation workup. For bilateral implantations, we recommend a sequential procedure. The second implantation will take place only if the vestibular function is preserved in the other side.