Since 1982, many countries have reported outbreaks or sporadic cases by enterohemorrhagic Escherichia coli (E. coli) serogroup strains, mainly E. coli O157 : H7. Hemorrhagic E. coli induces hemolytic uremic syndrome (HUS) in 10 to 15% of cases in infants and young chilidren. HUS is a clinical syndrome of hemolytic anemia, acute renal failure, and thrombocytopenia. We experienced a case of E. coli O8 as the causative organism of hemorrhagic colitis and hemolytic uremic syndrome in 16 year-old man. Hemorrhagic colitis was diagnosed by the sigmoidoscopy and E. coli O8 was identified in the stool culture. Hemolytic uremic syndrome was clinically diagnosed. A conservative management including total parenteral nutrition, plasma exchange transfusion, hemodialysis and continuous arteriovenous hemofiltration with dialysis resulted in a complete recovery of the patient. We herein report this manifestations of E. coli O8 and discuss the therapeutic issues related to hemorrhagic colitis and hemolytic uremic syndrome.