In Norway the number of deaths per year from drowning is approximately nine persons per 100,000, most of them men between 25 and 40 years of age. About 60% of these persons can swim, and 50% of the deaths are related to intake of alcohol. About 6% of the drowned are children, most of them boys. In disaster medicine, drowning is associated with accidents at sea, involving large vessels or small boats, or connected to offshore activities. The important pathological events are directly related to asphyxia, hypoxemia, hypercarbia, pulmonary oedema, and circulatory arrest. This paper describes various aspects of drowning and the pathophysiological processes involved, and discusses differences between drowning and near drowning in fresh water and salt water. Although treatment is basically centred on effective cardiopulmonary resuscitation, there are certain differences with regard to further treatment and fluid/electrolyte management. Hypothermia is often a prominent feature, and if cardiopulmonary resuscitation is successful, hypoxic brain damage may be ameliorated by the fall in body temperature.