The omphalomesenteric duct normally obliterates by the sixth week of intrauterine life. Incomplete obliteration results in various abnormalities which may be apparent in the newborn infant. These include fistula resembling ileum, a prolapsed loop of intestine through the umblicus and a fistula draining intestinal contents. The tract may contain ectopic tissue of stomach, colon or pancreas. Although this malformation should be recognizable at birth, 40 % of patients are not treated until after the first month of life. In the past 28 months since the Samsung Medical Center opened its doors to public, the authors have treated 4 cases of patent omphalomesenteric duct remnant including one case of T-shaped total prolapse of the duct and adjacent ileum. These cases will be discussed and the literature reviewed.