Background: There are only a few case reports from Germany of hemorrhagic shock and encephalopathy syndrome (HSES), whereas the incidence of this entity is probably much higher than reported. Thus, it seems necessary to describe further observations of patients with HSES. Methods: Seven patients (3 boys, 4 girls, aged 8 days to 9.5 months) were observed between 1987 and 1992, who fulfilled the diagnostic criteria of HSES. Their clinical data and laboratory findings were evaluated. Results: Diarrhoea preceeded onset of HSES in 4 patients, 3 patients had loose stools immediately after admission. Disturbed consciousness, severe shock, metabolic acidosis, fever and disturbed coagulation parameters were present in all of them. In 2 patients low concentrations of alpha-1-antitrypsin were found during the acute phase of HSES. Edema of the brain was diagnosed in 4 patients, additional cerebral infarction in 2 patients and cerebral hemorrhage in 1 patient. Three patients died, 3 of 4 survivors had severe brain damage. Conclusion: HSES is a clinical entity with unknown etiology, acute onset, fulminating course and poor outcome. Prognosis may be improved by thorough treatment of brain edema, shock and disseminated intravascular coagulation.