Dengue virus is the most important mosquito-borne viral disease in the world. Co-circulation of the four types of dengue viruses and expansion of dengue epidemic give rise to infection enhancement and a big expansion of clinical aspects of the disease. Infection with dengue virus (DENV) causes diseases ranging widely in severity, from self-limited dengue fever to life-threatening dengue hemorrhagic fever and dengue shock syndrome. But atypical manifestations of dengue fever are rising day by day but they may be under reported. Here in we report a case of 6 years old girl presented with sudden onset of abdominal pain and was diagnosed as classical dengue with ascites and pleural effusion. Pleural effusion and ascites are evidence of plasma leakage which appear in patients of Dengue hemorrhagic fever but not present in Classical Dengue or Dengue fever. Classical Dengue is a common disease in Bangladesh but there have been no reports of Dengue fever or Classical Dengue in association with pleural effusion and ascites.