Introduction: Meningoencephalitis is a syndrome leading to fatality and neurological damages. It is a severe neurological condition characterized by the simultaneous inflammation of the meninges and brain parenchyma., with infection being the most common cause of meningoencephalitis. The clinical presentation often overlaps with other central nervous system disorders, making timely diagnosis and treatment critical for patient survival and outcomes. The aim of this study is to determine the etiological causes of meningoencephalitis for facilitating early diagnosis and treatment. Materials and Methods: It is a prospective observational study, conducted in 180 cases, in a tertiary care hospital of North India. clinical examination was done followed by CSF culture, detection by Molecular biology techniques. Results: out of total 180, total positive case for infectious agents were 47, out of which bacterial Culture positive were 19. PCR positive viral case were 18 and bacterial positive case were 8, Tubercular aetiology were found in 2(4.25%), age group ranged from 5 days to 90 years. Majority of patients were males 119(66%).