Background: Seizure is one of the most important cause of admission to the emergency department (ED). The admission rate can be decreased by identifying the etiology of seizure which leads to appropriate treatment and elimination of the underlying cause. The purpose of this study is to survey the etiology of seizure in cases admitted to ED. Methods: This cross-sectional study was conducted on 150 patients with seizure admitted to Zahedan city hospital in 2015-16. Data were collected by a checklist including demographic, familial history, past medical history of seizure, cause and type of seizure, time of occurrence, status seizure and cause of recurrence which was completed for each patient. The data was analyzed by statistical methods in SPSS.16. Results: Among all of 150 patients 82 (54.6%) were male and 68 (45.3%) were female. The most common age group was 18-45 years with 114 (76%) patients. 74 (49.3%) patients had PMH of seizure and 15(10%) patients had positive FH of seizure. The most common cause of seizure was idiopathic epilepsy (47.3%), cerebral vascular lesions (14%), withdrawal and poisoning (6.7%). The other causes were paroxysmal non epileptic seizure, primary and secondary brain tumors, metabolic diseases, trauma each with prevalence of (5.3%). Congenital diseases (3.3%), infections (2.7%), demyelinating diseases (2%) and others (2.7%). The most common type of seizures was generalized tonic-colonic seizure (69%). (55.3%) seizures occurred in 6AM- 6PM. (4.6%) patients had status seizure. The most prevalent causes of recurrent seizure was related to inadequate drug use. Conclusions: The most common cause of seizure was idiopathic epilepsy and the next common causes were cerebral vascular lesion and withdrawal. Regular follow up of epileptic patients and eliminating the underlying cause and social abnormality will be effective in decreasing the occurrence of seizure.