BACKGROUND: Childhood cancer survivors (CCS) are a growing group of young individuals with a high risk of morbidity and mortality. We evaluated the prevalence and risk factors of hepatic late adverse effects, defined as elevated liver enzymes, in a large cohort of CCS. METHODS: The cohort consisted of all five-year CCS treated in the EKZ/AMC between 1966 and 2003, without hepatitis virus infection and history of veno-occlusive disease (VOD). Liver enzyme tests included serum levels of alanine aminotransferase (ALT) for hepatocellular injury and gamma-glutamyltransferase (γGT) for biliary tract injury. We performed multivariable linear and logistic regression analyses. RESULTS: The study population consisted of 1404 of 1795 eligible CCS, of whom 1362 performed liver enzyme tests at a median follow-up of 12 years after diagnosis. In total, 118 (8.7%) of 1362 CCS had hepatic late adverse effects defined as ALT or γGT above the upper limit of normal. Abnormal ALT and γGT levels were found in 5.8% and 5.3%, respectively. In multivariable regression analyses treatment with radiotherapy involving the liver, higher body mass index, higher alcohol intake and longer follow-up time were significantly associated with elevated ALT and γGT levels; older age at diagnosis was only significantly associated with elevated γGT levels (all p<0.05). CONCLUSION: One in twelve CCS showed signs of hepatic late adverse effects after a median follow-up of 12 years. Several risk factors have been identified. Future studies should focus on the course of long-term liver related outcomes and on the influence of radiotherapy and chemotherapy dose.