Two-hundred and thirty-six courses of high-dose chemotherapy with bone marrow transplantation for solid tumors in children were reviewed in order to assess the incidence of hepatic abnormalities and their etiology. Bacterial and fungal hepatitis were excluded from this study. Hepatic complications occurred after 43 courses (20 per cent) in 39 patients. Four patients had hepatic abnormalities after two consecutive courses. Predisposing factors were found to be conditioning regimen including busulfan and previous high dose chemotherapy. Veno-occlusive disease occurred in 11 children and had a fatal outcome in 4. In 9 children, hepatitis was a symptom of diffuse viral infection. In the other 23 courses, hepatitis was isolated but it was difficult to determine whether its etiology was viral (cytomegalovirus, Epstein-Barr virus, adenovirus, HBs, non A non B) or toxic. In these latter forms, the outcome was always good.