Sensorineural hearing loss is common in children with chronic renal insufficiency. The implantation of a CI is performed routinely in children with profound sensorineural hearing loss. A feared complication is a local infection with subsequent meningitis. Because of this risk, a successful implantation of a CI in children under immunosuppression after kidney transplantation has yet to be described. A four-yr-old boy with congenital renal dysplasia and posterior urethral valves, who was successfully transplanted with a kidney from his father at the age of two and a half yr, is presented. The boy had profound bilateral hearing loss before transplantation, most likely due to ototoxic antibiotic medication and long-term furosemide use. A hearing aid was insufficient; therefore, a CI was performed 20 months after the transplantation and no complications occurred in the 24 months of follow-up. This is the first report of a successful CI in a child after kidney transplantation.