Vertigo and dizziness are the most common complications of cochlear implantation. Data of a multicentric study about clinical aspects and cost utility were collected for vertigo and dizziness: incidence, clinical and treatment were analyzed among 469 adults and children. Results demonstrated that 16% of adults and 3% of children experienced dizziness postoperatively. In a few cases a specific mechanism as perilymphatic fistula was identified. In other cases the mechanism underlying delayed vertigo remains speculative and endolymphatic hydrops was suggested.