A series of 18 children suffering from persistent idiopathic neonatal hypoglycemia (PINH) is reported. Medical and surgical managements are described in detail. All patients subjected to surgery had failed medical treatment. These patients were divided into two groups: 1) 85% pancreatectomy leaving the uncinate process in situ, and 2) 95% pancreatectomy leaving a small rim of pancreatic tissue along the duodenum and the common bile duct. The spleen was preserved in all cases. Two out of 5 children of group 1 required further resection of the pancreas for persistent hypoglycemia and were converted to 95% pancreatectomy. Since 1981 95% pancreatectomy was exclusively employed. Only one patient required insulin for 3 weeks postoperatively. Histopathology and immunohistochemistry revealed islet cell dysplasia and islet cell nuclear hypertrophy in the majority of cases, 35% of the patients had focal adenomatosis. Better control of hypoglycemia is achieved by primary 95% pancreatectomy and, thus, 95% pancreatectomy is recommended as the initial procedure in the treatment of PINH.