ObjectiveTo analyze the clinical data of 5 cases of congenital hyperinsulinemia with sizures as the initial symptoms. MethodsRisk factors in perinatal period, clinical manifestation, laboratory examination, treatment and follow-up visits of 5 cases of congenital hyperinsulinemia with sizures as the initial symptoms were analyzed retrospectively, who were admitted to Department of Neurology of Jiangxi Children's Hospital from July 2012 to August 2016. Results5 children were all male. The onset time varied from 3 to 9 mouths old. All the cases presented seizures as the main clinical manifestations, persistent hypoglycemia, hyperinsulinemia, low free fatty acid and hypoketonemia. During follow-up, treatment with diazoxide and dietary therapy was effective in 3 cases, pure dietary therapy ineffective in 2 cases. 3 cases manifested as acute symptomic seizures, 2 cases as remote symptomic epilepsy. During follow-up, 1 cases showed normal intelligence, 3 cases developmental delay, and 1 case dropout. ConclusionMost of the infants with congenital hyperinsulinemia presented seizures as initial symptoms. Severe hypoglycemia and long duration would damage brain, and early management may significantly improve the prognosis. The early diagnosis can be made by measuring fasting blood glucose, insulin, free fatty acid and, plasma β-hydroxybutyric acid, C peptide and so on. The majority of children were effective by diazoxide.