Between 1974 and 1988, 86 newborns with perforated necrotizing enterocolitis (NEC) were treated by either laparotomy (usually involving a bowel resection and a temporary stoma) or a peritoneal drain under local anesthesia. The survival of babies in the laparotomy group was 57% versus 59% in the drained group. However, for neonates less than 1,000 g survival in the drained group was 69% compared to 22% for the laparotomy group (P <.01). As the weight of the babies increased over 1,000 g, the survival in the laparotomy group increased to 67%. There was no significant increase in survival in infants over 1,500 g. The highest neonatal mortality risk is generally found among babies weighing less than 1,000 g at birth with a gestational age of less than 30 weeks. This risk increases even more when perforated NEC is added to the prematurity. With the use of peritoneal drainage, survival in this group can approach that of larger neonates.