Despite major advancements in surgery and anesthesia, the risk of mortality following cardiac and non-cardiac surgery remains high and is frequently associated with perioperative organ dysfunction. Neurological derangements range from brief postoperative delirium to postoperative cognitive dysfunction to perioperative stroke with associated impact on quality of life and mortality. Major adverse cardiac events and arrhythmias play a significant role in adverse clinical outcomes following all surgical procedures. GI dysfunction represents one of the more common complications following surgery, while hepatic dysfunction remains infrequent but largely uninvestigated. Perioperative endocrine dysfunction consists of both hyperglycemia and hypoglycemia, both of which can have significant effects on perioperative course and recovery. Postoperative pulmonary complications remain one of the more common perioperative complications depending on patient-related and surgical factors. Perioperative acute kidney injury is common in the perioperative setting. This chapter briefly explores the impact of cardiac and non-cardiac surgery on individual organ systems and some of the effects of these perturbations on perioperative morbidity and mortality.