Appropriate anaesthesia, the controlled and reversible suppression of sensation and consciousness, is essential for the safe and effective performance of surgeries, procedures and experiments involving nonhuman primates. It requires detailed knowledge of physiology, pharmacology and technical management to maintain stable physiological conditions and minimise stress for the animal. This chapter provides a comprehensive overview of the major types of anaesthesia, their mechanisms of action and the associated physiological responses, as well as airway management, including endotracheal intubation in nonhuman primates, anaesthetic equipment and breathing systems. Effective management of anaesthesia is essential to ensure both animal safety and welfare, as well as the reliability of experimental outcomes.