Dengue fever is one of the most common arthropod-borne viral infectious diseases. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, Southeast Asia and the Western Pacific with an estimated two fifths of the world's population being at risk. The notable endemic viral hemorrhagic fevers (VHFs) found in West Africa, including yellow fever, Lassa fever, Rift Valley fever, dengue fever and until recently Ebola have been responsible for most outbreaks with fatal consequences. These VHFs usually produce unclear acute febrile illness, especially in the acute phase of infection. In this context, early detection of infection with sensitive and specific laboratory tools and the prompt clinical management of this disease is a health care priority. Rapid and accurate methods for the diagnosis of dengue fever are important for optimum patient management and institution of early preventive strategies. In this review we tried to focus on role of Molecular methods in early and definitive diagnosis of dengue.