Cochlear implantation has become the standard procedure for the treatment of severe to profound hearing loss, even in patients with underlying diseases. We report the case of a CI patient who underwent cardiac defibrillation, following which he reported a reduction in sound quality, a worsening of tinnitus, as well as headaches. An integrity test showed multiple electrode anomalies which could not be directly attributed to the cardioversion. We performed explantation and reimplantation of the CI. During the course of rehabilitation, the patient showed good results in speech comprehension. Since cardioversion, like any electrical monopolar treatment, may damage CI, it should be avoided in CI patients wherever possible. If it cannot be avoided, we strongly recommend removing the sound processor during treatment sessions. When device-related problems occur, the treatment of choice is reimplantation.