Background: Acute onset seizure is one of the common causes of childhood hospitalization with significant mortality and morbidity. There is limited data regarding acute seizures episodes and its outcome from developing countries. Current study aims to find the common etiology of seizure and classify seizure types in various age groups. It was also aimed to find outcome in relation to diagnosis, abnormal imaging, EEG and requirement of monotherapy or polytherapy. Material and Method: This was a hospital based prospective study carried out in the department of Pediatrics, Calcutta National Medical College and Hospital from June 2016 to May 2017. Children aged 1 month to 12 years presented with acute onset seizure were enrolled. Variables collected were demographics, clinical presentation, laboratory tests, brain imaging, elect- roencephalography, diagnosis and therapy. The data was analysed using Statistical Package for the Social Sciences (SPSS) for Windows version 16.0 (SPSS Inc ; Chicago, IL, USA). Results: A total of 491 patients were admitted for acute onset seizure with 289(58.8%) males and 202(41%) females. Among these patient 280(57%) presented with fever and 55(10.9%) children presented with status epilepticus. Generalised onset tonic clonic was the most common seizure type, central nervous system infection was the most common etiology in all the age groups. Final outcome was made at the time of discharge as discharged without sequelae, dischaeged with sequelae and death. Patient with CNS infection had highest mortality. Conclusion: CNS infection and febrile seizure were common cause of seizure in fewer than 5 children. Group of children presenting with unprovoked seizure require long term follow up studies including neurophysiologic studies and neuroimaging for better understanding of childhood seizure disorder in developing countries.