This retrospective study compared the liver function test results and outcomes between children with acute liver failure (ALF) due to dengue hemorrhagic fever (DHF) and due to other causes. We retrospectively reviewed patients less than 15 years old with a diagnosis of ALF admitted to 13 participating centers from different parts of Thailand for the years 2000 and 2001, and those admitted to King Chulalongkorn Memorial Hospital for the year 1997 to 2004. The diagnosis of ALF was based on prothrombin time (PT) prolongation to greater than 2 times the normal control value and the presence of encephalopathy without pre-existing liver disease. The patients were divided into 2 groups: group I (n=16) had DHF with ALF and group II (n=37) had ALF due to other causes. DHF patients had AST levels significantly higher than ALT levels. The mortality rate in group I (50%) was lower than in group II (72.9%), although the difference was not statistically significant. The non-DHF patients who died had a significantly longer duration of jaundice before the onset of encephalopathy and a significantly higher PT ratio compared to survivors. There were no significant differences in the duration of jaundice before the onset of encephalopathy and liver function between dengue patients who died and those who survived.