Dengue usually presents itself with subclinical or mild infection to full blown dengue fever (DF) to dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). In Kolkata, dengue started in 1824 followed by five epidemics that occurred in 1836, 1906, 1911, 1923 and 2005. The aim of this investigation is to study the clinicohematological correlation of all patients with respect to their gender that were admitted to “Kali Pada Chowdhury Medical College and Hospital” during 2012 epidemic. Amongst a total of 1237 dengue patients (either dengue Nonstructural protein1 antigen or dengue Immunoglobulin M positive) that were admitted to the hospital, 11 patients died within 48 hours of admission; hence they have been excluded from the study. DHF patients were divided into males and females. During admission, proper history, physical examinations with necessary hematological investigations were performed and repeated again after 24-48 hours. After collection of all the reports, correlations of the collected data were carried out. 170 and 1056 patients were diagnosed with DF and DHF respectively; significant symptoms and signs were headache, backache/myalgia, nausea/vomiting, loose motion and anorexia hepatomegaly. Hemoglobin level was low in females, leucopenia observed in 79.52% patients and thrombocytopenia seen in 57.58% and 86.13% patients during and 24-48 hours after admission respectively. 96 and 97 DHF patients showed evidences of ascites and plural effusion respectively. In 2012 epidemic, 86.13% patients suffered from DHF, headache, backache, nausea/vomiting, loose motion and anorexia were predominant symptoms. Significant number of patients had leucopenia; only few showed evidence of plasma leakage.