We report two cases of acute renal failure in patients with nonfulminant acute hepatitis A. First case is a healthy 25 year-old man complained of myalgia and jaundice. Initial laboratory results showed BUN 40 mg/dL, creatinine 5.23 mg/dL, AST 2,220 IU/L, ALT 3,530 IU/L, total bilirubin 6.26 mg/dL, and positive anti-HAV IgM antibody. Supportive treatments including fluid therapy were started. Serum creatinine and total bilirubin levels were 7.98 mg/dL and 7.66 mg/dL respectively on the 5th hospital day, and decreased gradually. He was discharged on the 12th hospital day, and was being followed up in outpatient department. Second case is a 33 year-old woman who admitted for bilateral flank pain, high fever, nausea, and vomiting. She was diagnosed as acute pyelonephritis and acute hepatitis A. On admission, BUN 13 mg/dL, creatinine 0.74 mg/dL, AST 3,720 IU/L, ALT 2,280 IU/L, total bilirubin 0.9 mg/dL were noted, and acute renal failure developed next day. Fluid therapy with antibiotics administration were started, and maximal BUN and creatinine was 41.7 and 8.09 mg/dL respectively on the 8th day. She recovered without dialysis and was discharged on the 19th hospital day. Proper and prompt comprehensive supportive measures would decrease the need for dialysis in patient of acute renal failue associated with acute hepatitis A.