Vascular lesions of the gastrointestinal (GI) tract include arterio-venous malformations as angiodysplasia and Dieulafoy's lesion, venous ectasias (multiple phlebectasias and haemorroids), teleangiectasias which can be associated with hereditary hemorrhagic teleangiectasia (HHT), Turner's syndrome and systemic sclerosis, haemangioma's, angiosarcoma's and disorders of connective tissue affecting blood vessels as pseudoxanthoma elasticum and Ehlers-Danlos's disease. As a group, they are relatively rare lesions that however may be a major source of upper and lower gastrointestinal bleeding. Clinical presentation is variable, ranging from asymptomatic cases over iron deficiency anaemia to acute or recurrent bleeding that may be life-threatening. Furthermore, patients may present with other symptoms, e.g. pain, dysphagia, odynophagia, the presence of a palpable mass, intussusception, obstruction, haemodynamic problems resulting from high cardiac output, lymphatic abnormalities with protein loosing enteropathy and ascites, or dermatological and somatic features in syndromal cases. Diagnosis can usually be made using endoscopy, sometimes with additional biopsy. Barium radiography, angiography, intraoperative enteroscopy, tagged red blood cell scan, CT-scan and MRI-scan may offer additional information. Treatment can be symptomatic, including iron supplements and transfusion therapy or causal, including therapeutic endoscopy (laser, electrocautery, heater probe or injection sclerotherapy), therapeutic angiography and surgery. The mode of treatment is of course depending on the mode of presentation and other factors such as associated disorders. If endoscopic or angiographic therapy is impossible and surgical intervention not indicated, pharmacological therapy may be warranted. Good results have been reported with different drugs, albeit most of them have not been tested in large trials.