PURPOSE: Benign Convulsions with mild Gastroenteritis(CwG) were first reported in Japan by Morooka in 1982. The condition is recognized as a distinct clinical entity. It is characterized by previously healthy infants and young children aged 6 months to 3 years having afebrile brief generalized tonic-clonic convulsions between the first and the fifth sick days of viral gastroenteritis usually in winter. The patients are less than 5% dehydrated and the seizures tend to occur repetitively over several days with no eleptic discharges in the interictal electroencephalograms. The tests for rotavirus antigens in stool are frequently positive and other laboratory results are normal including cerebrospinal fluid, serum electrolytes and blood glucose. Also, they are known to have a good prognosis. The study intends to compare the clinical symptoms of CwG with normal body temperature and with high body temperature because mild gastroenteritis can induce fever. METHODS: The subjects were 42 patients diagnosed as GwG, who were admitted to Soonchunhyang University Hospital from May 2003 to March 2006. A Cohort study was performed and their characteristics were examined in terms of frequency, sex, age, monthly distribution, body temperature, days in hospital, seizure tups and duration, number of convulsions in one gastroenteritis period, family history, past history, and other symptoms of gastroenteritis RESULTS: The Total number of patients with gastroenteritis in the period were 635 and only 42(6.6%) patients were diagnosed as CwG. The mean age was 17.1+/-4.7 months, and it commonly occurs in winter. the typical symptoms of gastroenteritis were vomiting and diarrhea with 34(81.0%) patients having both symptoms simultaneously. Less vomiting and more diarrhea were noticed after seizure. Rotavirus antigens were positive in 18(51.4%) patients, and the number of seizures was 2.0+/-1.3 times during one gastroenteritis period. There were found no statistical differences in age, sex, days in hospital, seizure types and duration in those groups with and without fever and of pisitive and negative rotavirus antigens. CONCLUSION: CwG was defined as nonfebrile convulsions with gastroenteritis until nowadays, but there are no statistical differences between febrile and nonfebrile CwG. Therefore, febr ile seizures with gastroenteritis can be included in the same category of CwG.