Cardiac surgery involves a spectrum of open, minimally invasive, and endovascular procedures designed to restore adequate perfusion and optimize cardiac function in patients with complex coronary, valvular, and aortic pathology. This chapter reviews contemporary operative strategies for coronary artery bypass grafting, including conduit selection and arterial versus venous grafting, and outlines approaches to aortic, mitral, and tricuspid valve repair and replacement across diverse clinical scenarios. The role of cardiopulmonary bypass is discussed, highlighting key circuit components and the physiologic consequences of hemodilution, systemic inflammatory activation, coagulopathy, and end-organ dysfunction. Common and high-impact postoperative complications are examined with emphasis on early recognition and targeted management. These include postpericardiotomy syndrome, pericardial and pleural effusions, cardiac tamponade, chest tube management, vasoplegic syndrome, postoperative atrial and ventricular dysrhythmias, and chylothorax. For each complication, relevant pathophysiologic mechanisms, clinical manifestations, diagnostic evaluation, and stepwise medical or surgical treatment strategies are summarized. Across the perioperative continuum, vigilant hemodynamic and rhythm surveillance, prompt interpretation of imaging and laboratory data, and protocolized responses to decompensation are essential to mitigate morbidity and mortality. The chapter underscores the importance of multidisciplinary collaboration among surgeons, anesthesiologists, intensivists, advanced practice providers, nurses, and allied health professionals to deliver timely, coordinated care. By integrating foundational surgical principles with complication-focused algorithms, this chapter provides a practical framework to support clinical decision making, enhance patient safety, and meaningfully improve short- and long-term outcomes after adult cardiac surgery.