Dengue viruses are icosahedral in structure and contain a single-stranded positive- sense RNA sequence of 11kb inside their capsid protein, which belongs to Flaviviridae family, genera Flavivirus. DENV a vector dependent viral virus which presents a severe health danger worldwide. Objective: To study the different strains of dengue on the basis of serotypes Methods: A cross sectional study was conducted at a tertiary care hospital Lahore, Primary and Secondary Health Department Lahore. The blood samples of 103 patients were collected from non-random sampling technique to check out the data of different parameters such as WBC’s & Platelets through Complete Blood Count (CBC), NS1 from ELISA and nature of dengue strains through RT- PCR. Results: Of 103 positive dengue patients, there were n= 58 (33.63 ± 16.54) males and n=45 (40.64± 16.00) females. Data for the total patients is subjected to statistical differences by Paired t-test (*p<0.05). The overall percentage of dengue strains within the sample population was DENV-2 (96%), DENV-3 (2%), DENV-1 & DENV-2 (2% in females, nil in males) DENV-2 & DENV-3 (2% both in males and females). According to clinical parameters the correlation of ELISA results with WBC’s was significant (<0.0001) as well as ELISA and platelets of patients had no correlation with each other. Conclusions: Leukopenia and Thrombocytopenia is found particularly in DENV-2 strain as well as we found two different strains in two patients. So, our research work is helpful for the identification in genetic similarity of dengue strains.