We conducted a hospital-based study from June 2002 to December 2006 of Thai children aged 1-15 years with acute hepatic failure (AHF) to determine the causes and outcomes. Eleven children were included in the study. Hepatitis B virus was the cause of AHF in one child, infection-associated hemophagocytic syndrome was the cause in 1 child, Wilson's disease was the cause in 1 child and dengue fever was suspected to be the cause in 2 children. In 6 children the cause of AHF was unknown. Jaundice was reported in 9 of 11 children. Ten of 11 children had mild to moderate encephalopathy on admission. Five of 11 children died due to AHF. No liver transplantations were performed among the children in this study. Further studies into the relationship between dengue infection and AHF are needed.