Heart failure is a complex clinical condition caused by structural or functional cardiac disorder to fill and eject blood from the ventricle, heart is enable to provide body with needed blood amount. This condition is very common in the world, among adults and children. There are numerous causes of pediatric heart failure and can be divided into categories involving ventricular dysfunction (including heart contractility and heart rate), volume overload (preload) and pressure overload (afterload). Also, another categorization can be based on the age of children. In heart failure compensatory mechanisms are activated (renin-angiotensin-aldosterone system – RAAS and adrenergic nervous system) and over period of time they can lead to heart remodeling, decreased myocardial extensibility and contractility and worsening of heart failure. Clinical symptoms vary due to child’s age, but the most common are tachycardia, poor perfusion, poor weight gain, then tachypnea, use of accessory respiratory muscles, grunting and nasal flaring in infants because of pulmonary congestion and hepatomegaly, jugular venous distension and peripheral edema due to systemic congestion. The diagnosis of heart failure in children is based on characteristic physical findings, imaging studies and laboratory studies. The initial evaluation includes echocardiography, chest radiography, electrocardiogram and complete blood count. Heart failure therapy protocol depends on its etiology and stage. The therapy includes surgical, pharmacologic (diuretics, digoxin, ACE inhibitors, angiotensin receptor blockers, beta-blockers, inotropic agents), nonpharmacological (positive pressure ventilation, mechanical circulatory support or heart transplantation) approach. It is important to highlight not only general therapy approaches which are useful in decreasing different kind of difficulties that follow this condition, but also prevention and therapy of complications and circulatory shock therapy. Guidelines and therapy management are mostly developed on studies in adult population due to lack of pediatric patients and also because of the accompanying problems that occur during conducting a research among them. However, the child’s organism does not function in the same way as the adult’s, so it is important to collect as much information about heart failure in children as possible to gain important knowledge, especially about pathogenesis, diagnosis and treatment.