The incidence of emetic episodes during the first 24 h after anaesthesia was studied prospectively in 485 children aged 0–16 years in relation to age, premedication, type of induction, type and duration of anaesthesia, type of surgery and use of postoperative analgesics. The incidence of emetic episodes was 25% in the whole material. The majority of the emetic episodes were recorded after the immediate recovery period. In children under 2 years of age, vomiting was only recorded in 5%. Nausea and vomiting was most common after squint surgery (75%) and least common after endoscopies (17%). Neither premedication with diazepam nor the method ofinduction (thiopentone, i.v., thiopentone rectally, inhalation with halothane) influenced the incidence of nausea. For the same type of surgery, maintenance of anaesthesia with halothane resulted in a lower incidence of nausea than anaesthesia with fentanyl‐pancuronium.