Necrotizing enterocolitis--a highly letal disease in the newborn period--is diagnosed in about 1--2% of the admissions to a nursery. The marcroscopic lesions are basically necroses predominantly found in the ileum, colon and jejunum. Untreated they lead to perforation, peritonitis and sepsis. The predisposing factors include such as perinatal complications, immaturity and umbilical vein catheterization; the main symptoms are bile stained vomiting and blood-streaked diarrhea, followed by signs of fulminant sepsis and peritonitis. The most typical roentgenographic findings are intramural air (pneumatosis intestinalis) and in more advanced cases pneumoperitoneum (free peritoneal air) and portal vein gas. The current plan of management--consisting of immediate withdrawal of oral feeds, gastric suction, intravenous fluid therapy, treatment of shock and administration of antibiotics--and the indication for operation are discussed. Perinatal stress and secondary bacterial invasion of the intestinal lesions seem to play an important role in the etiology of the disease. An early nutrition of the healthy immature with human breast milk seems to reduce the incidence of necrotizing enterocolitis or at least has a mitigating influence on the later course of the disease. The mortality in our own series--as reported--was high (6 patients: 1 survivor, mortality: 83%) as 4 of the patients were admitted with gross symptoms of intestinal perforation and severely shocked.