SummaryA prospective interview-based survey on the incidence of postoperative nausea and vomiting in 1107 in-patients aged 4-86 years was conducted during a 3-month period. Nausea, emetic episodes and the need for anti-emetic medication were recorded for 24 h postoperatively. In the recovery room, the incidence of nausea and vomiting was 18% and 5%, respectively. Over the whole 24-h period, these figures were 52% and 25%, respectively; severe nausea was experienced by 8%. The highest incidence of emetic sequelae was observed in gynaecological patients; 52% of the 822 patients who received general anaesthesia and 38% of the 285 patients who received regional anaesthesia reported nausea. The most important predictive factors associated with an increased risk for nausea and vomiting were female gender, a previous history of postoperative sickness, a longer duration of surgery, nonsmoking and a history of motion sickness. Based on these five items, a simple score predicting the risk of nausea and vomiting was constructed with a moderately good discriminating power. Nausea and emetic episodes still persist as the most common complaints following anaesthesia and surgery. Many adults find postoperative nausea and vomiting even more distressing than postoperative pain. The overall incidence of postoperative nausea and vomiting in the recovery room is around 10% [1] but ranges from 20% to 30% during the first 24 h after surgery according to recent reports [1][2][3][4]. Despite the advances in modern anaesthetic practice and surgical techniques, there is still room for improvement in identifying the causative factors as well as in the prophylaxis and treatment of this problem.The objective of this epidemiological survey of postoperative complications was to get representative numerical estimates of the present incidence of postoperative nausea and vomiting for different types of common surgical procedures in a tertiary care setting. The aim was also to analyse the predictive factors associated with these symptoms and to construct a risk score based on patient-related factors, as well as on some key anaesthetic and surgical factors. Methods