Neonatal diabetes is a rare cause of hyperglycemia in the neonatal period. It is caused by mutations in genes that encode proteins playing critical roles in normal functions of pancreatic beta cells. Neonatal diabetes is divided into temporary and permanent subtypes. Treatment is based on the correction of fluid-electrolyte disturbances and hyperglycemia. Patients respond to insulin or sulfonylurea treatment according to the mutation type. Close glucose monitoring and education of caregivers about diabetes are vital.