The aim of our study was to assess the clinical, biochemical and virological profile of patients with atypical viral hepatitis A (protracted, relapsed and cholestatic forms). Five patients with the relapsed form and 2 patients with the cholestatic form were studied among 95 patients hospitalized in our Division of Infectious Diseases for viral hepatitis A during the years 1988 to 1998. A relapse was defined by a decrease in serum alanine transaminase levels > or = 50% followed by a > or = 50% increase in the minimal value. The protracted form was defined by elevated serum alanine transaminase levels for more than 6 months. The cholestatic form was defined by the highest value of bilirubinemia above 15 mg/dL or by a persistent jaundice for more than 8 weeks. All 5 of the protracted-relapsed forms had a biphasic course: the median time between onset and relapse of the disease was 8 weeks, and serum aminotransferase activities returned to the normal range within an average of 45 weeks after relapse. The two cholestatic forms were characterized by a very high level of bilirubinemia (24.58 and 19.03 mg/dL) and by protracted jaundice with itching (3 and 8 months). All patients were tested for hepatitis B and C, Cytomegalovirus and Epstein-Barr virus, with negative results. In short, viral hepatitis A is a benign, self-limiting disease which usually resolves in a few weeks. In a non-negligible percentage of cases (3-21%), however, it can assume atypical forms, which are more serious in patients with chronic liver diseases.