Shock can be due to a variety of etiologies and is encountered frequently in the Emergency Department, Operating Room, and Pediatric Intensive Care Unit. Parameters of vital signs such as blood pressure, respiratory and heart rates, quality of perfusion, and mental status are frequently incorporated in descriptions of shock. However, the best unifying definition is an acute state of circulatory dysfunction that results in the inability to meet tissue metabolic demands. When dealing with a child in shock, this concept will help guide the evaluation, assessment, and treatment. Of equal importance in treating the patient with shock is time. A rapid evaluation, assessment, and treatment, especially when dealing with hypovolemic or septic shock, are paramount to a favorable outcome.