Propofol by continuous intravenous infusion was used as an alternative to nitrous oxide/oxygen for conscious sedation in 19 patients undergoing out-patient dental treatment. Patients were either extremely anxious or mentally and/or physically handicapped. Propofol was administered by a syringe pump at an initial rate of 3 mg/kg/hour. During the procedure the infusion rate was adjusted to attain and maintain the desired level of conscious sedation. The mean time from starting the propofol infusion until reaching the required level of sedation was 11.5 (SD 3.5) minutes. The mean infusion rate was 3.6 (SD 0.65) mg/kg/hour. The average duration of the dental procedure was 55.9 (SD 18.8) minutes. Sedation was satisfactory in all but two patients. There were no side-effects. Recovery was rapid after stopping the infusion. It is concluded that propofol is an acceptable alternative to nitrous oxide/oxygen for conscious sedation in the dental surgery.