Postoperative nausea and vomiting (PONV) is still a problem and is very discomforting for the patients. As surgery done on out-patient basis becomes more frequent, PONV will represent an important factor in the length of recovery room stay, and is in this way an economic problem. Based on the literature from 1985-1995 factors associated with increased risk, prevention and treatment of PONV are discussed in view of the physiological mechanisms. The conclusion is that PONV is a complex problem. It demands an individual evaluation with a careful preoperative visit including planning of both preanaesthetic and anaesthetic agents. Furthermore, a proper anaesthetic treatment of the per- and postoperative course is of high importance. Patients at high risk of PONV should be identified and given prophylactic antiemetics.