Arterial oxygen saturation (SaO2) was measured in 50 healthy children undergoing dental extractions under general anaesthesia. An inhalational anaesthetic technique was employed, with an inspired oxygen concentration of 33%. There were decreases in SaO2 of greater than 5% of the baseline value in 70% of patients, and greater than 10% in 26% of patients. The majority of these decreases were associated with teeth extractions or during placement of dental prop and pack. Non-Caucasian children showed a significantly (p less than 0.05) greater maximum decrease in SaO2 from baseline value compared to Caucasian children. The maximum decreases in SaO2 from baseline value in children anaesthetised by supervised dental students, and in children whose extractions were performed by dental students, were significantly (p less than 0.05) greater than in children whose anaesthetic and surgery were performed by members of staff.