A preoperative evaluation is advised for all children and adolescents having elective surgery with anesthesia. The evaluation assesses medical and psychosocial factors that may affect surgery timing and identifies underlying conditions that may require evaluation or management before surgery. The evaluation also classifies the patient's American Society of Anesthesiologists' risk category. The history component of the evaluation should include a review of the patient's medical, behavioral, and social history; previous complications with surgery or anesthesia; a medication review; and a tobacco use history. The physical examination should involve the identification of airway anomalies that could interfere with intubation and the evaluation of cardiac, respiratory, neurologic, and fluid status. Routine laboratory testing is not recommended for healthy children and adolescents having low-risk procedures. Patients with underlying conditions may benefit from targeted laboratory and imaging studies to assess clinical stability. The HEMSTOP questionnaire can identify patients who have coagulation disorders. A pregnancy test should be considered for all adolescents who are postmenarchal on the day of surgery. Many children have anxiety about surgery, which can be reduced by educational pamphlets, videos, coaching provided to parents the week before surgery, and a parental presence during the induction of anesthesia.