Between 1980 and 1994, 540 patients with acute viral hepatitis were admitted to hospital at the Department of Infectious Diseases of Catania (eastern Sicily). Twenty-five patients out of 540 were assessed as having non-A, non-B, non-C hepatitis. These subjects were studied for anti-HEV IgM and IgG seroprevalence by testing serial serum samples collected 1, 4, 12 and 24 weeks after the onset of acute disease. Fourteen of 25 samples (56%) seroconverted to anti-HEV IgG antibodies. No sample was positive for anti-HEV IgG at week 1, ten samples were positive at week 4 and the remainder at week 12. Anti-HEV reactivity was maintained until week 24 in all cases. In 11 of the 14 patients seroconverting to anti-HEV, the presence of IgM anti-HEV was found, which appeared in the sample from week 1 and gradually disappeared thereafter. Identified risk factors for HEV transmission included travel in the tropics and shellfish ingestion (anti-HEV positive versus anti-HEV negative: p < 0.05). HEV-related hepatitis is not yet a major public health problem in Sicily but, from our data, the trend of its incidence is clearly upwards. The high incidence of faecally-orally transmitted diseases in Sicily, the crucial position of Sicily in the middle of the Mediterranean Sea (where HEV largely circulates) and the increase of migration from developing countries are all factors which should increase awareness for a more active surveillance of the spread of HEV in our area.