Clinical and laboratory features of 66 patients with sporadic hepatitis A were evaluated from October 1978 to July 1981. Jaundice was reported in 88.6% of the patients, and the frequency of skin rash was 15.7%. Less than 5% atypical lymphocytes were noted in 29.5% of the patients. Proteinuria and hematuria were present in 23.4% and 6.3% of the patients. However, immune complexes were not detected in their sera. One of the patients who had hematuria developed acute renal failure. About 10% of the patients transiently showed both low levels of cholinesterase and cholesterol and prolongation of the prothrombin time. There was no patient with fulminant hepatic failure. Liver function tests returned to normal except for 3 patients within 3 months. For 10 months after the onset, slight elevation of SGPT peristed in the patient with acute renal failure and also in a patients with a previous history of liver disease. One of two patients with acute intrahepatic cholestasis showed protraction of mild hyperbilirubinemia more than 6 months after the onset of acute illness.