The frequency of necrotizing enterocolitis (NEC) in the extremely premature infant (less than 1,000 g) is still high and it is very difficult for infants weighing less than 1,000 g with NEC perforation to survive. In our institutes, the management protocol for NEC perforation in infants weighing less than 1,000 g includes peritoneal drainage under local anesthesia, administration of coagulating factor XIII, and the usual treatment for septic shock. During the past 3 years, four infants weighing less than 1,000 g with NEC perforation have survived using this protocol without laparotomy. This management protocol is the treatment of choice in infants in very poor condition or infants weighing less than 1,000 g with NEC perforation.