Near-drowning and drowning are major causes of neurologic injury and death in young persons. Most victims aspirate water, and pulmonary edema develops in many of these cases. Prolonged submersion causes cerebral asphyxia and adversely affects the brain within five minutes. Immediate ventilation and oxygenation are essential in the reversal of cerebral anoxia. During field resuscitation, precautions should be taken to protect the cervical spine because of the possibility of injury. The Heimlich maneuver is used only after unsuccessful attempts at ventilation suggest foreign-body obstruction. Prehospital advanced cardiac life support with tracheal intubation is indicated in patients with severe injuries. On arrival at the hospital, ventilation with continuous positive airway pressure or positive end-expiratory pressure enhances pulmonary function. Many water submersion accidents are avoidable; close supervision of infants and toddlers, installation of a fence around home swimming pools, and abstinence from alcohol during participation in water sports are some practical precautions.