Internists and hospitalists are central to perioperative care, bridging medical optimization with surgical and anesthetic decision-making. Despite the expanding complexity of surgical patients, most internists receive limited formal exposure to anesthesia. This knowledge gap has implications for risk stratification, clinical communication with anesthesiologists, and the prevention and management of postoperative complications. Anesthesiology principles—airway management, hemodynamic control, anesthetic drug effects, and postoperative monitoring—are directly relevant to internists who co-manage surgical patients. Furthermore, postoperative complications such as delirium, myocardial infarction, hypoxemia, and acute kidney injury frequently fall under the internist’s scope. This chapter outlines the rationale for a structured anesthesia primer for internists, emphasizes the multidisciplinary nature of perioperative medicine, and frames the goals of the text: to enhance collaborative care, improve patient safety, and empower internists to participate confidently in perioperative decision-making.