Postoperative nausea and vomiting (PONV) is considered as a main cause of dissatisfaction after surgery with postoperative pain. Overall incidence of PONV is 30%, and the incidence rate can increase up to 70-80% in high-risk patient groups. The causes of PONV are multifactorial and can largely be categorized as patient risk factors, surgical procedure, and anaesthetic technique. Pharmacological treatments including dopamine antagonist, anti-histamines, anticholinergics, dexamethasone, neurokinin-1 antagonists, and serotonin antagonist are used to prevent and treat PONV. This article reviews the prevalence, mechanisms, and risk factors of PONV, and how to prevent and treat it.