Angiography is a useful diagnostic tool in cases with massive gastrointestinal bleeding such as angiodysplasia and varicosis when endoscopy is not available. Angiodysplasia and varicosis have distinguishable characteristic features on angiography, such as the presence of a nidus, visible late-draining veins, and the typical vascular tuft. We recently treated a rare case of congenital angiodysplasia without the characteristic angiodysplasia features on angiography. Instead, the patient presented with a very rare case of idiopathic jejunal varicosis. A 42-year-old woman visited the emergency room with the chief complaint of melena for three days and a hemoglobin level of 5.9 g/dL. An abdominal CT angiogram showed varicosis at the jejunal mesentery. Angiography of the superior and inferior mesenteric arteries showed tortuous and dilated jejunal and ileal branches during the venous phase, suggesting a vascular malformation such as varicosis of the jejunum. Surgical exploration with intraoperative endoscopy revealed diffuse engorged veins and a 1.0-cm-diameter superficial ulcer covered with a blood clot that was 70 cm from the ligament of Treitz. A 100-cm segment of jejunum was resected. Histological examination revealed that the lesion was angiodysplasia, not varicosis. The final diagnosis was congenital angiodysplasia. (Gut and Liver 2009;3: 122-126)