More than one quarter of neonates and older children in the United States (USA) are anemic prior to surgery, with significantly worse outcomes and increased mortality, compared to nonanemic children. Iron deficiency anemia is the most common type of anemia in children worldwide. The optimal Hgb value in pediatric patients before an elective surgical procedure is unknown. Assessment of anemia tolerance is complex and best achieved through consideration of the individual patient’s clinical context. Routine preoperative laboratory testing is recommended if a planned surgery has a high risk for bleeding or presents a significant risk for associated cardiopulmonary or neurologic complications. Once anemia is diagnosed, it should be managed to optimize the patient’s surgical outcome, preferably weeks before surgery and under the guidance of a pediatrician or hematologist to ensure follow up.