From January 1986 through December 1988, we have seen 7 cases of isolated intestinal perforation in 250 infants with birth weights less than 1,000 g (3% incidence) without histological or clinical evidence of necrotizing enterocolitis (NEC). Patients had a mean birth weight of 670 g, gestational age of 25.1 weeks, and sustained a perforation at a chronological age of 10.4 days. No infants had been fed. A definite, blue-discolored abdomen was the only consistent clinical sign (n = 7). Free intraperitoneal air on radiograms was rarely observed (n = 1). Abdominal ultrasounds (n = 3) and metrizamide contrast studies (n = 3) were not diagnostic. The presence of an umbilical artery catheter (7/7), falling hematocrit (6/7), thrombocytopenia (5/7), and a positive diagnostic paracentesis were most commonly found. In 6 of 7 patients, this perforation was associated with coagulase-negative staphylococcal sepsis. Surgical or histological diagnosis showed focal perforation in either the terminal ileum (n = 4) or the transverse and descending colon (n = 3). Survival was 3 of 7; 2 patients died of intracranial hemorrhage and 2 died of Candida sepsis. We conclude that (1) intestinal perforation can occur in the absence of NEC; (2) bluish discoloration of the abdomen is the most reliable clinical finding; and (3) perforation may be associated with coagulase-negative staphylococcal infection.