This is a retrospective study of the gastrointestinal symptoms, signs and laboratory parameters in adult dengue patients admitted to Kuala Lumpur Hospital from 1st December 2004 to 31st December 2004. Clinical and laboratory parameters that may predict the need for intensive care were investigated. Six hundred sixty-six patients with clinical and biochemical features consistent with dengue infection were identified. Patients were stratified into those who required intensive care and those who were managed in non high dependency wards. Serum alanine aminotransaminase (ALT) levels were normal in 22.8% of patients and 5.9% of patients had acute fulminant hepatitis. More patients with dengue haemorrhagic fever (DHF) had elevated ALT levels as compared to patients with classic dengue fever (DF) (p = 0.012). Patients with DF had a statistically significant lower mean ALT level as compared to patients with DHF. Abdominal pain (p = 0.01) and tenderness (p<0.001), gastrointestinal bleed (p<0.001), jaundice (p<0.001), hepatomegaly (p<0.001) and ascites (p<0.001) were predictors of need for intensive care. We conclude that gastrointestinal manifestations are very common in dengue patients. Presence of abdominal pain and tenderness, gastrointestinal bleed, jaundice, hepatomegaly and ascites can be used to triage patients requiring intensive care.