Segmental intestinal dilatation (SID) is a rare pathologic finding, which causes intestinal obstruction in newborn period and gastrointestinal bleeding, anemia, abdominal pain, malabsorption, and growth failure in older children. We present a case of SID causing hypoproteinemia.A 10-year-old girl presented with recurrent abdominal distension since she was 8.5 months old. She was diagnosed to have protein-losing intestinal lymphangiectasia. Result of physical examination was normal except moderate growth retardation. Her blood workup showed depletion in total protein, albumin, and globulin levels. Gastrointestinal series revealed a dilated segment of small intestine, and Tc(99m)-pertechnetate scintigraphy detected ectopic activity in abdomen. The patient was taken to operation with the presumptive diagnosis of intestinal duplication. A dilated segment of ileum was encountered, and segmental resection and anastomosis were performed.Patient was discharged on the postoperative fourth day and remains well. Histopathologic examination of the specimen revealed SID.Segmental intestinal dilatation is an uncommon congenital anomaly. Most of the cases were operated on in newborn period because of intestinal obstruction, and their diagnoses were made perioperatively; the others were diagnosed in older ages during the investigation of nonspecific symptoms. The index patient is the second case of SID having hypoproteinemia in the literature. Gastrointestinal series suggested the diagnosis, and segmental resection and anastomosis were the adequate treatments.