Postoperative nausea and vomiting (PONV) continues to be a clinical problem with an unacceptably high incidence. Several studies have been performed that compare different antiemetics but thus far no successful monotherapy has been found. The reason for this is that the genesis of PONV is multifactorial and that patient characteristics and type of anesthesia and surgery may have an influence. It is possible to quantify the risk of PONV for a given patient using available risk score systems. In patients at great risk it is meaningful to recommend prophylactic antiemetics with a 2- or even 3-drug regimen, e.g. droperidol, ondansetron and dexamethasone. If the patients experience PONV despite treatment or prophylaxis, they should be treated with a drug from a group different from the one used earlier.