This review covers 42 patients with fulminant hepatitis treated at the Clinic of Infectious Diseases of University of Pavia over a period of 11 years (1975-1985). This group is 1.9% of the 2181 subjects hospitalized for viral hepatitis, and consists of 25 males (59.5%) and 17 females (40.5%) with a mean age of 44 years. 26 patients (62%) had a virus B hepatitis, whereas in the remaining 16 the non-B type was diagnosed. B hepatitis had an overall prevalence of 56.4%. No case of fulminant hepatitis showed prothrombin levels above 23 (overall average 14%) and bilirubin below 17 mg/dl (overall average 24.5 mg/dl). SGOT and SGPT values were 1684 and 1868 UI/l respectively. 24 patients (57.1%) developed coma after admission to hospital and 18 had this diagnosis upon entry. History evidenced a heroin habit for 6 patients (14.2%); antiblastic treatment for 13 (30.9%); a preexisting liver disease for 7 (16.6%); other major pathologies for 6 (14.2%); steroid anabolizers, barbiturates + pirazolone derivatives and oral contraceptives use for 4 (9.5%) respectively. The overall mortality rate was 90.5%. 17 subjects (40.4%) were treated in an intensive care unit with a mortality rate of 75%.