Hemolytic uremic syndrome (HUS) can be clinically classified into two types: typical cases with a diarrheal prodrome of association with E. coli O157, and atypical cases without antecedent diarrhea. However, HUS is not common in Taiwan. To evaluate the clinical course, complications and outcome of HUS in children, and to identify the risk factors for mortality, retrospectively, seven cases of HUS in our hospital in the past 6 years were studied. Six of them were boys, and one was a girl. Their ages ranged from 0.67 to 3 years. None of them were preceded by diarrheal prodrome. Acute renal failure, hypertension and liver involvement were noted in all cases. Stroke and seizure developed in three of the cases with sequelae. Two cases progressed into end-stage renal disease (ESRD). One case developed acute respiratory distress syndrome (ARDS). Two cases (28.5%) expired. ESRD especially associated with ARDS was highly related to mortality.