Necrotizing enterocolitis (NEC) is a serious condition affecting predominantly the premature infant. The purpose of this study is to report a multicenter experience of complications in 252 infants requiring surgical therapy for NEC. Data from eight institutions for the years 1980 through 1990 were collected and analyzed for infants undergoing surgical therapy for NEC. Records were reviewed for gestational age, birth weight, age at operation, indications for operation, degree of intestinal involvement, operation(s) performed, complications, and 30-day mortality rates. A total of 264 infants underwent surgical intervention for NEC during the study period. Complete information was available for 252 patients. The mean gestational age was 31 +/- 5 weeks and the mean birth weight was 1,552 +/- 823 g. The mean age at operation was 18 +/- 35 days. Pneumoperitoneum was the most common indication for operation (42%). The 30-day survival rate was 72%. Eighty-one percent of patients underwent primary laparotomy, whereas peritoneal drainage was performed in 48 (19%) patients. Postoperative complications were identified in 119 (47%) patients. The most common postoperative complications were sepsis (9%), intestinal strictures (9%), and short gut (9%). Wound infections occurred in 6%, and the incidence of intraabdominal abscess formation was only 2.3%. Gestational age < 27 weeks (P < .005) and birth weight < 1,000 g (P < .005) were associated with significantly increased mortality but no increase in postoperative morbidity. The incidence of complications was similar in the very low birth weight (< 1,000 g) infants (51%) compared with infants > or = 1,000 g (46%).(ABSTRACT TRUNCATED AT 250 WORDS)