Twenty-five non-smokers and 35 smokers who had abstained overnight from cigarette smoking and were undergoing minor elective orthopaedic surgery were studied in order to compare gastric volume and pH. There was no significant difference in aspirated volume and pH both just after intubation and prior to extubation between the two groups, thus indicating that habitual smokers undergoing elective surgery in general anaesthesia do not have increased risk of acid pulmonary aspiration compared with non-smokers.