We retrospectively analysed 33 children and adolescents who had been hospitalized in a liver transplant unit within the previous 10 years for acute liver failure (ALF). The patients' age varied between 2 months and 15 years of age (median 6.2 +/- 5.3), and 21 (63%) were male. Thirteen patients (39%) were immunoglobulin-M anti-hepatitis A virus (HAV) sero-positive. Eleven cases (33%) had an undetermined aetiology. The 13 children with HAV ALF were between 17 months and 15.6 years of age (median 5.8 +/- 4.6) and eight were male (61.5%). All were on a list for urgent liver transplant. Of these, five (38%) died while waiting for a liver. Only one patient recovered spontaneously. Seven patients received a liver transplant; three died in the immediate postoperative period and one died 45 days after transplant. Three children are alive 1, 2 and 5 years after transplant. We conclude that HAV was the most frequent cause of ALF, which had high mortality even when a liver transplant was possible. The results support universal HAV vaccination in this area.