Aim: to evaluate the clinical profile and outcome of AES in hospitalized children. Material and Methods: This Cross-sectional, observational study was done the Department of Paediatrics, Anugrah Narayan Magadh Medical College and Hospital, Gaya, Bihar, India, from March 2017 to November 2017. Children between age 1 month to 14 years with the acute onset of fever and a change in mental status such as confusion, disorientation, coma or inability to talk and/or new onset of seizures (excluding simple febrile seizure) were included in study. All cases were investigated Cerebrospinal Fluid (CSF) analysis, dengue serology, and Radiological investigation as per clinical presentation. Results: Among 150 AES cases most of them were above 10 years of age (32.67%). Majority of them were males 100(66.67%), and 50(33.33%) were females. Most of the cases were reported during monsoon period 82(54.67%), followed by post-monsoon 50 (33.33%) and premonsoon 18(12%). out of 150 cases, all had fever; 110 (73.33%) had altered sensorium; 88 (58.67%) had convulsion; 40 (26.67%) had headache; 62 (41.33%) had vomiting. On fundus examination 48 (32%) showed papilledema. Out of 150 cases 81(54%) had viral etiology, 35(23.33%) had dengue, 9(6%) had malaria, 5 (3.33%) bacterial etiology, 10 (6.67%) had tuberculosis, 8 (5.33%) had other causes. Those patients who had shock and need inotropes showed significant mortality (pvalue: 0.017). Conclusion: Majority of cases were in the age-group of above 10 years, with male predominance. The peak in occurrence of cases was during post-monsoon period.