Background: The Dengue is a mosquito borne viral infection and transmitted, primarily by Aedes aegypti and sometimes by Aedes albopictus. Objective: To evaluate hematological changes in patients suffering from acute dengue infection with serological confirmation. Methods: It is a prospective study at tertiary urban hospital. Clinically suspected cases of dengue with serological confirmation during the period from May 2014 to February 2016. Results: Majority of the cases having dengue infection belong to the age group of 1–20 years. Males (61%) were more affected than the females (39%). DF was the most common manifestation (79%), DHF is lesser (17%) and DSS is the least (4%). The thrombocytopenia was seen in 15% of the dengue positive cases. In DSS the hematocrit level lies in the upper limit of normal.