Three children suffered from acute onset of convulsions and progressive coma associated with hyperpyrexia, profound shock and generalized bleeding tendency. No causative agent could be identified. Despite aggressive resuscitation they all died. Post-mortem examination revealed cerebral oedema, petechial haemorrhages of the gut, lungs and kidneys, and a generalized depletion of lymphocytes in the lymphoid organs. Features were compatible with haemorrhagic shock encephalopathy, which is a highly fatal disease. The possible role of hyperpyrexia in its pathophysiology is discussed. More careful case identification and research in various possible aetiological factors may help elucidate its pathogenesis.