A bilateral sensorineural (perceptive) deafness occurred in a 12-year-old girl, following laparoscopic appendicectomy under general anaesthesia not comprising nitrous oxide and low insufflation pressures and a normal haemodynamic status. There was neither a personal nor a familial history of hearing disturbances nor a preoperative intake of ototoxic drugs. The initial loss of 50 dB has been substantiated by evoked auditive potentials. The treatment consisted of hyperbaric oxygenotherapy and vasodilators. The girl recovered completely. Finally the etiology of this complication remained unrecognized. Possibly the CO2 insufflated into the abdominal cavity could be considered. However, its causative effect remains to be proven.