We describe a case of fatal peritonitis due to Clostridium difficile in a neonate. Although the patient had several clinical features that were compatible with the diagnosis of neonatal necrotizing enterocolitis, examination of the bowel at laparotomy disclosed that a mesenteric band caused the patient's underlying disease. Postmortem histopathologic tests revealed gram-positive rods in the wall of the small intestine. Clostridium difficile was the only organism recovered from an antemortem culture of peritoneal fluid and was also recovered from a postmortem blood culture.