This document summarizes post operative nausea and vomiting (PONV). It discusses the anatomy and physiology involved in vomiting, including the chemoreceptor trigger zone and neurological pathways. It identifies common risk factors for PONV and scoring systems to predict risk. It then describes the mechanisms and uses of different drug classes for preventing and treating PONV, including 5-HT3 receptor antagonists, butyrophenones, dexamethasone, and neurokinin-1 receptor antagonists. It concludes by mentioning other strategies for reducing PONV incidence such as acupuncture, multimodal antiemetic prophylaxis, and opioid-sparing analgesia techniques.