Preoperative assessment and optimization represent critical steps in modern perioperative medicine, ensuring patient safety and guiding surgical and procedural decision-making. The primary goals are to identify perioperative risks, optimize comorbidities, and facilitate shared decision-making regarding surgical/procedural appropriateness and planning. A detailed history and physical examination remain the cornerstone, with emphasis on functional capacity, comorbid conditions, medication use, and prior procedural and anesthetic complications. Functional status, often quantified in metabolic equivalents, is a powerful predictor of perioperative outcomes, while the American Society of Anesthesiologists Physical Status Classification provides a widely used framework for risk communication. Current guidelines promote a stepwise, individualized approach, discouraging routine testing in favor of targeted evaluation guided by procedural urgency, active cardiac conditions, surgical risk, functional capacity, biomarkers, and validated risk calculators such as the Revised Cardiac Risk Index (RCRI) and National Surgical Quality Improvement Program (NSQIP). Special attention must be directed to patients with valvular heart disease, heart failure, coronary artery disease, arrhythmias, pulmonary hypertension, pulmonary disease, and renal and hepatic dysfunction, where perioperative risk is especially elevated. Perioperative medication management, including antithrombotic agents, beta-blockers, angiotensin converting enzyme (ACE) inhibitors/angiotensin receptor blocker (ARBs), and glucocorticoids, requires careful coordination between internists, anesthesiologists, and surgeons. Beyond clinical optimization, preoperative assessment increasingly emphasizes shared decision-making, integrating patient values and goals into perioperative planning. Internists, with their longitudinal patient relationships, are uniquely positioned to support this process. Ultimately, safe surgical care arises from multidisciplinary collaboration, evidence-based risk assessment, and thoughtful optimization of chronic disease in the perioperative context.