This chapter provides an extensive overview of antiemetic pharmacology, addressing the management of nausea and vomiting across diverse clinical scenarios encountered in anaesthetic and perioperative care. The chapter initially explores the neuroanatomy and receptor-based physiology underlying the emetic reflex, detailing afferent pathways including the chemoreceptor trigger zone, gastrointestinal tract, vestibular system, higher cortical centres, and baroreceptors. The pharmacological mechanisms and clinical indications of key antiemetic classes—such as serotonin (5-HT₃) antagonists, dopamine (D₂) antagonists, histamine (H₁) antagonists, muscarinic (M₁) antagonists, neurokinin (NK₁) antagonists, steroids, and cannabinoids—are examined comprehensively. Special attention is given to commonly utilized agents, including ondansetron, dexamethasone, cyclizine, metoclopramide, domperidone, prochlorperazine, and aprepitant. The chapter emphasizes multimodal antiemetic strategies, particularly in postoperative nausea and chemotherapy-induced emesis, while highlighting critical side effects such as extrapyramidal symptoms, QT prolongation, and sedation. This chapter equips trainees with the knowledge necessary to effectively manage nausea and vomiting, enhancing patient comfort and safety during the perioperative period.