Necrotizing enterocolitis (NEC) is a disease of the premature neonate that requires early therapy, sometimes even surgery and therefore early diagnosis. In general, plain radiography of the abdomen and sonography are valuable imaging techniques for diagnosis of NEC. Course of NEC: The disease starts with distension of small bowel loops. Furthermore the children develop pneumatosis in the bowel wall, which is a nonspecific pattern. If the NEC persists, the air passes into the portal vein system, causing a pneumoportogram. Finally, the disease can lead to perforation. In doubtful cases, the plain radiogram must be repeated within a period of 6 h. With sonography distension of the bowel, thickening of and pneumatosis in the bowel wall, the pneumoportogram and free intraperitoneal fluid can be easily depicted. The most common complications of NEC are intestinal stenosis and strictures that can lead to ileus. Differential diagnosis: Focal perforation of ileum, volvulus and Hirschsprung's disease are some of the differential diagnoses.