A case of acute respiratory obstruction in the immediate postoperative period is described in a young woman who emerged from general anaesthesia after a Caesarean section for fetal distress. She had a pregnancy complicated by disabling polyhydramnios and anxiously anticipated the birth of a child with a diaphragmatic hernia, diagnosed antenatally. The cause of the airway obstruction was functional in nature as confirmed by flexible fibreoptic laryngoscopy. The diagnosis, paradoxical vocal cord motion, has to be considered as an infrequent cause of postoperative airway obstruction; its recognition and treatment are discussed. The patient did not have a history which might have indicated its possible occurrence. It is suggested that paradoxical vocal cord movement in a more mild form may be overlooked as cause for postoperative stridor and airway obstruction.