Droperidol (Dehydrobenzperidol, Dehidrobenzoperidol, Dridol, Droleptan, Inapsine) is a dopamine D(2) receptor antagonist that has been widely used in adults and children for the prevention and treatment of postoperative nausea and vomiting (PONV) over several decades and, more recently, for the prevention of opioid-induced PONV during patient-controlled analgesia (PCA) in adults. In well controlled clinical trials of patients undergoing surgery, the efficacy of single-dose intravenous (IV) droperidol in preventing PONV was similar to that of ondansetron and dexamethasone. Droperidol significantly reduced opioid-induced PONV in adults during PCA and had a morphine-sparing effect. Droperidol is generally well tolerated and the incidence of adverse effects is similar to that observed with placebo and the serotonin 5-HT(3) receptor antagonists (setrons). Guidelines recommend that, in adults, droperidol monotherapy be considered for those at moderate risk of PONV, and droperidol in combination with a setron and/or dexamethasone be considered for patients at moderate or high risk of PONV. In children with moderate or high risk of PONV, droperidol is recommended for first-line use in some countries, and second-line use in others.