Background: Neonatal seizure is a rare neurologic condition. The current study aimed at determining the etiology of neonatal seizure.Methods: The current study evaluated the data of 100 neonates who were hospitalized at neonatal intensive care unit (NICU) during 2015-2017. A pediatric neurologist made the final diagnosis of seizure. Patients’ medical records were used to review neonatal seizure variables. SPSS (version 16) was used to perform the statistical analyses.Results: The current study enrolled 100 newborns (41% female) admitted to the NICU following the first episode of seizure and the body temperature of 36.8-39.2°C (mean: 37.2°C). Of 100 participants, 94 (94%) had acute symptomatic seizure and 6 (6%) were compatible with neonatal epilepsy syndrome criteria. According to the results, the commonest etiologies were the neonatal encephalopathy and hypoxic-ischemic encephalopathy constituting 82% of participants.Conclusion: The consequences of acute symptomatic seizures in neonates are determined mainly by the etiology of the seizures. Seizure burden and use of anti-seizure drugs may also have some impact, but this has yet to be fully defined