To provide a comprehensive review of dengue, with an emphasis on clinical syndromes, classification, diagnosis, and management, and to outline relevant aspects of epidemiology, immunopathogenesis, and prevention strategies. Dengue, a leading cause of childhood mortality in Asia and South America, is the most rapidly spreading and important arboviral disease in the world and has a geographic distribution of > 100 countries.Boolean searches were carried out by using PubMed from 1975 to March 2009 and the Cochrane Database of Systematic Reviews from 1993 to March 2009 to identify potentially relevant articles by key search terms such as: "dengue"; "dengue fever"; "dengue hemorrhagic fever"; "dengue shock syndrome"; "severe dengue" and "immunopathogenesis," pathogenesis," "classification," "complications," and "management." In addition, authoritative seminal and up-to-date reviews by experts were used.Original research and up-to-date reviews and authoritative reviews consensus statements relevant to diagnosis and therapy were selected.We considered the most relevant articles that would be important and of interest to the critical care practitioner as well as authoritative consensus statements from the World Health Organization and the Centers for Disease Control and Prevention. Dengue viral infections are caused by one of four single-stranded ribonucleic acid viruses of the family Flaviviridae and are transmitted by their mosquito vector, Aedes aegypti. The clinical syndromes caused by dengue viral infections occur along a continuum; most cases are asymptomatic and few present with severe forms characterized by shock. Management is predominantly supportive and includes methods to judiciously resolve shock and control bleeding while at the same time preventing fluid overload.Dengue is no longer confined to the tropics and is a global disease. Treatment is supportive. Outcomes can be optimized by early recognition and cautious titrated fluid replacement, especially in resource-limited environments.