Isoflurane was compared with halothane as the sole supplement to anaesthesia with nitrous oxide and oxygen for outpatient dental extractions in 80 children. Induction and maintenance of anaesthesia were satisfactory with both agents, although there was a higher incidence of coughing, salivation and laryngospasm in the group receiving isoflurane. However, in contrast to predictions from the physical properties of isoflurane and halothane, immediate recovery was significantly slower in patients who had received isoflurane. Recovery was complicated by coughing in a significant number of patients in the isoflurane group. The incidence of reported complications during later recovery was similar with both agents, apart from the complaint of non-specific postoperative aches in a significant number of patients to whom isoflurane was administered.