Shock remains a significant cause of morbidity and potential mortality in the pediatric population. It is defined as a impaired perfusion with a too high oxygen demand in comparison to oxygen delivery. The cause of hypoxia may be found in a hypovolemic condition due to hemorrhage or loss of gastro-intestinal fluids, a disorder in volume distribution or a cardiac dysfunction. Less frequent are patients with an obstruction in the outflow tract of the heart or disorders in binding oxygen to hemoglobin. Hypoxia leads to lactat-acidosis with the clinical signs of tachypnoea, tachycardia and restlessness. It is of greatest importance to recognize the ongoing dysfunction early, in spite of mechanism of compensation with a high cardiac output, warm periphery and dry skin (warm shock). Is there no adequate therapy decompensation will occur with vasoconstriction, cold periphery and low cardiac output. This will lead to multiple organ dysfunction syndrome with neurological, renal, further cardiac, pulmonary and metabolic disorders. If this point of no return is reached, cell death will continue to occur and the patient will die. Early and aggressive volume therapy is indicated, filling the cardiac system with crystalloids or colloids. Later on under clinical conditions inotropic drugs will improve cardiac output and oxygen delivery. Only by recognizing these patients as early as possible we will be able to reduce morbidity and mortality of this potentially dangerous syndrome.