In the tropical and subtropical area, dengue virus is mostly found. To the determination of the occurrence of dengue viral infection and hematological profile of dengue infected peoples in the Dhaka city. A sum of 255 samples of blood from both sex and different age groups were collected in this research. Dengue nonstructural protein 1 (NS1) and complete blood count (CBC) test were performed for the study. During this study period, total 255 samples were tested. Among these, 67samples were diagnosed as positive. Seroprevalence of dengue was 26.30%. Out of 67 positive dengue patients, 41 (61.2 %) were male and 26 (38.8 %) were female. Dengue infection was observed more in 21 to 30years age group followed by above 40years and 16 to 20years but observed less in of 1st day to 5years followed by 11 -15years, then 6 -10years and 31 - 40years. It was seen that the >40years of age group had the maximum unit of cases having low platelet count followed by 21-30years and it was also seen that 21-30years of age group had the maximum range of cases having low WBC count followed by above 40years of age group. In our research, we showed thrombocytopenia (100000 - 150,000/μl) with leucopenia (White Blood Cells, WBC <5000/μl) in 8(26.6%) cases and thrombocytopenia (100000-150,000/μl) without leucopenia in 9 (24.3%) cases but thrombocytopenia (<100000/μl) with leucopenia (White Blood Cells (WBC) < 5000/μl) in 5(16.7%) cases and thrombocytopenia (<100000/μl) without leucopenia in 6 (16.2%) cases. Among 67 positive cases, we found that (26.6%) had DF and (16.7%) had DHF according to WHO classification. For validating more reliability, this research needs further work.