BACKGROUND: The influence of preoperative starvation on blood glucose concentrations in children remains controversal. This period varies from 6 to 12 hr or even more, in different institutions. A surgical operation causes a rise in the blood glucose concentration, and this increased concentration returns to normal within 8 to 12 hr. The purpose of the present study was to investigate blood glucose concentra tions in children undergoing elective surgery who fasted before anesthesia. METHODS: One hundred sixty-five healthy children, aged less than 7 yr, and scheduled for elective minor surgery were included in the study. Blood samples were collected before induction of anesthesia, after induction of anesthesia and at the recovery room. The correlation between the period of starvation and the blood glucose concentration was estimated and hypoglycaemia was defined as a blood glucose concentration less than 40 mg%. RESULTS: The duration of starvation ranged from 10 to 14 hr in the majority of the patients (66.7%). The duration of starvation beyond 14 hr was 7.8%. No significant correlations were obtained between preoperative blood glucose concentrations and duration of starvation. None of the patients were hypoglycaemia before surgery. The intraoperative and postoperative blood glucose concentrations were significantly higher than the preoperative blood glucose concentration. CONCLUSIONS: In children less than 7 yr, blood glucose concentrations were not influenced by duration of starvation within a 14 time period.