The technological advances of medicine in the last decades have allowed interventions to be carried out in patients who were previously out of reach. Preanesthetic evaluation is the responsibility of the anesthesiologist, and considers information from multiple sources: clinical history, interview, records, physical examination and preoperative tests. It allows to know the history of the patient, to identify modifiable risk factors and to develop an anesthetic plan in relation to the findings to reduce perioperative morbidity and mortality; educate, improve satisfaction, and reduce patient anxiety; avoid unnecessary delays or suspensions; coordinate visit to another consultant, if requires; and obtain signed informed consent. The tendency is not to request “routine preoperative testing”, but rather tests based on precise indications, which depend on the patient and the type of surgery. In relation to preoperative fasting, the update ASA recommendations seek to improve patient comfort, decrease the risk of dehydration and hypoglycemia from prolonged fasting, and minimize the risk of aspiration of gastric contents. The cardiac patient undergoing non-cardiac surgery has higher perioperative morbidity and mortality compared to the general population; here the anesthetic evaluation is key in the reduction of perioperative risk, since our decision to perform additional studies, management and specific interventions will depend on the outcome in this subgroup of patients. Surgical “prehabilitation” and “frialty” are emerging concepts that include preoperative physical, nutritional and psychological optimization, to improve postoperative recovery process, instead of the more traditional approaches, that target the postoperative period for “rehabilitation”.