In 2009, the World Health Organization (WHO) revised its dengue guidelines and proposed severe organ impairment as one category of severe dengue in addition to severe plasma leakage and severe bleeding [1] . Severe liver involvement was defined as AST or ALT$1000 units/liter (U/L). In Taiwan, AST.10 times the upper limit of normal (ULN) occurred in 11% of dengue patients [6] , while in Brazil this occurred in 4% of their cohort [3] . In this study, we aimed to evaluate the clinical relevance of elevated AST and ALT levels and correlate liver aminotransferase levels with dengue severity according to WHO 1997 and 2009 classifications.