Having reviewed 47 cases of vascular malformations of the stomach and duodenum, we propose an endoscopic classification for these lesions: Pattern I (flat or slightly protruded, bright red lesions with frond-like margin) is the most usual form of presentation. The "telangiectatic form" (pattern II) is an endoscopic variation, with the same clinical and, possibly, pathogenic significance. Submucosal nodular forms (pattern III) are the most difficult to diagnose and treat. Electrocoagulation is the most pertinent treatment.