Introduction: Dengue fever is a re-emerging viral disease commonly occurring in tropical and subtropical areas. The clinical features and abnormal laboratory test results of dengue infection are similar to those of other febrile illnesses; hence, its accurate and timely diagnosis for providing appropriate treatment is difficult. Delayed diagnosis may be associated with inappropriate treatment and higher risk of death. Early and correct diagnosis can help improve case management and optimise the use of resources such as hospital staff, beds, and intensive care equipment. The goal of this study was to develop a predictive model to characterise dengue severity based on early clinical and laboratory indicators using data mining and statistical tools. Objective: To find out clinical Profile and laboratory indicators in children on admission based Predicting the severity of dengue fever. Methods: We retrieved data from a study of febrile illness in children in Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh Of 325 febrile episodes recorded, 198 patients were confirmed to have dengue. A classification and regression tree (CART) was used to construct a predictive decision tree for severe dengue, while logistic regression analysis was used to independently quantify the significance of each parameter in the decision tree. Results: This study was 325 patient admissions during the study year, of which 251 (77.23%) met the inclusion criteria. Clinical manifestations of 198 patients with dengue infection, including 38 with severe disease. Of these, 74 (22.76%) were not enrolled, leaving 125 febrile episodes in 180 children, with 144 children having a single episode, 31 children having two episodes, one child having three episodes, and four children having four episodes. A decision tree algorithm using haematocrit, Glasgow Coma Score, urine protein, creatinine, and platelet count predicted severe dengue with a sensitivity, specificity, and accuracy of 60.5%, 65% and 64.1%, respectively. Conclusions: The decision tree we describe, using five simple clinical and laboratory indicators, can be used to predict severe cases of dengue among paediatric patients on admission. This algorithm is potentially useful for guiding a patient-monitoring plan and outpatient management of fever in resource-poor settings.