Diffuse vascular ectasia of the gastric antrum may present as occult gastrointestinal blood loss and iron-deficiency anemia. Four patients are described with iron-deficiency anemia in whom characteristic lesions were found at endoscopy. As in previous reports, lesions are either angioid linear streaking of the antrum with convergence at the pylorus ("watermelon stomach") or diffuse, well-demarcated erythematous areas. Biopsy with the electrocautery forceps may show dilated ectatic mucosal vessels often containing fibrin thrombi which will establish a diagnosis. Standard biopsy techniques failed to make a diagnosis in two of the three patients in which it was attempted. Medical therapy consisted of iron replacement and transfusion as needed. In three of the four cases, symptomatic anemia recurred and required antrectomy for management of the anemia. The antrectomy specimens revealed ectatic mucosal and submucosal vessels with a fibrotic pattern involving the lamina propria. This pattern has been previously reported. One patient was treated with corticosteroids transiently with resolution of her anemia. The endoscopic appearance of this entity may mimic antral gastritis and needs to be considered in the differential diagnosis of iron-deficiency anemia from chronic gastrointestinal blood loss.