Milrinone inhibits human heart phosphodiesterase 3 and phosphodiesterase 4 with similar potency. By increasing cAMP concentration, they have similar actions as the ? receptor agonists dobutamine and epinephrine, but tend to lower systematic and pulmonary vascular resistance more than do the catecholamines. The vasodilation due to milrinone is related to increased levels of cAMP in vascular smooth muscle. Milrinone is used for short term treatment of acute low cardiac output after cardiac surgery due to septic shock. Milrinone is administered by continuous intravenous infusion and its dosage consists in a loading dose followed by a maintenance infusion in infants and children. Milrinone is efficacy and safe in infants and children but it may induce adverse-effects. The effects of milrinone in infants and children have been extensively studied: milrinone improves oxygenation and myocardial performance, milrinone is used to treat pulmonary, ventricular dysfunction, and tachyarrhythmias. The pharmacokinetics of milrinone have been studied in infants and children and the elimination half-life is 3.1 hours in infants aged < 1 year and 1.9 hours in children. The treatment of infants and children with milrinone has been extensively studied: milrinone treats hypoxemic respiratory failure and reduces diastolic arterial pressure, milrinone has been successfully used in infants and children undergoing heart surgery, and milrinone prevents death or low cardiac output syndrome in children undergoing surgery for congenital heart disease. The aim of this study is to review the milrinone dosing, efficacy and safety, effects, adverse-effects, pharmacokinetics, and treatment in infants and children.