Anemia affects more than 269 million children globally, including 1.2 million children in the United States. Although anemia can present with numerous symptoms, children are most often asymptomatic at the time of diagnosis. Anemia in infants and children most often arises from nutritional iron deficiency but can also be a result of genetic hemoglobin disorders, blood loss, infections, and other diseases. In the United States, newborn screening programs assess for various genetic causes of anemia at birth. The US Preventive Services Task Force notes insufficient evidence to recommend universal screening of asymptomatic children in the first year of life; however, the American Academy of Pediatrics recommends screening all children before 1 year of age. Initial laboratory evaluation consists of a complete blood cell count, with further testing dependent on mean corpuscular volume. Microcytic anemia is the most common hematologic disorder in children, with iron deficiency as the most common cause. A recommended dosage of 2 to 6 mg/kg per day of ferrous sulfate is the most effective oral iron supplementation for patients with iron deficiency anemia. Delayed cord clamping at birth might prevent early iron deficiency, but no clinically relevant outcomes are certain. Normocytic anemia is classified by reticulocyte count and can reflect hemolysis (high reticulocyte count) or bone marrow suppression (low reticulocyte count). Macrocytic anemia is less common in children and is typically a result of nutritional deficiencies or poor absorption of cobalamin (vitamin B₁₂) or folate. Pediatric hematology referral might be beneficial for patients who do not respond to treatment, and referrals are critical for any bone marrow suppression that is diagnosed.