<p>Preoperative medicine which includes comprehensive medical evaluations and optimizations of medical conditions before surgeries is an evolving specialty of medicine. Preoperative medicine is practiced by a variety of specialists, varies widely in efficacy, but should be evidence based and individualized based on the patient, and the planned anesthetic and surgery. Innovations in procedural and surgical care are evolving rapidly. And, the demand for anesthesia for even minor procedures continues to expand. Specialized services are increasing, but often lead to fragmented care. These confluences predispose to complications and poor outcomes. Preoperative medicine is filling a gap to meet the needs of perioperative physicians to evaluate and prepare patients for anesthesia, surgeries and procedures. Increasing age, numbers of comorbidities and the extent of surgery combine to increase the risk of perioperative morbidity and mortality. This review cannot address every factor that predicts risk, but is designed to be highlight some of the most common or controversial conditions.</p>