Dengue is the most important viral vector transmitted disease world wide in terms of morbidity and mortality. According to WHO around 5,00,000 cases of DHF(Dengue hemorrhagic Fever) and DSS(Dengue Shock Syndrome) occur annually with 22,000 deaths. It is found that some individuals have only undifferentiated fever while others progress to DHF. Our study is an attempt to find out the factors that determine the severity of dengue in our population. Among the 50 individuals with dengue fever that were studied those with hypertension, diabetes, renal failure and alcohol abuse tended to have severe dengue.