Laboratory diagnosis of dengue virus infection is based mainly on serological tests. They are relatively inexpensive and easy to perform as compared to culture and nucleic acid based methods. In the primary infection, anti-dengue IgM antibodies are produced from fifth day of infection and remain in circulation for 60-90 days. Anti-dengue IgG antibodies are produced after one week, attain maximum after 2-3 weeks and remain lifelong in circulation. In secondary infection, IgG antibodies are detected at high levels in acute stage while IgM antibodies are present at low levels. The present study was conducted in Department of Microbiology, Anugrah Narayan Magadh Medical College (ANMMC), Gaya, Bihar, India. The 1350 patients suspected with dengue fever from October 2017 to September 2018 the study period of 12 months were included in the study. A single blood sample approximately 2-3 ml was collected from each patient in a plain vacutainer tube with all aseptic precautions. Serum was subjected to IgG and IgM anti dengue antibodies by dengue IgG capture enzyme linked immunosorbent assay (ELISA) and dengue IgM capture ELISA. From the present study it can be concluded that the serological prevalence of the dengue fever in the patients admitted to ANMMC Gaya is 7.41%. In the affected populations had majority of males and mid aged populations. The maximum cases are from monsoon season. This may be due to the increases breading of mosquitoes during the rains. Early diagnosis of infection can prevent life threatening complications and immunological assays such as the IgM capture ELISA is a reliable method for diagnosis of dengue virus infection.