The clinical efficacy and tolerability of gastroprotected ferritin were assessed in children affected by iron deficiency and/or sideropenic anemia. Forty-seven children with iron-deficiency and/or sideropenic anemia were included in the study and were treated with gastroprotected ferritin at a dose of 4-5 mg/kg/day per os for 4 months. Only 33 children correctly completed the entire treatment cycle, achieving a marked improvement of blood parameters (increased Hb, accompanied by higher levels of sideremia and in particular ferritin, with a contemporary decrease in erythrocytic protoporphyrin and transferrinemia) and clinical symptoms, especially pallor, anorexia, debility, somnolence, hyperactivity, disturbed sleep and excessive sweating. Of the remaining 14 children, 9 failed to present for the planned control after the 4 months of therapy, 3 abandoned therapy due to difficulties of assumption and 2 because of intolerance phenomena, such as nausea and diarrhoea. In conclusion, gastroprotected proteoferrin is efficacious and well tolerated in the treatment of iron deficiency in children.