This is an account of 20 cases of MWS, representing 8% of a series of 247 consecutive upper GI-bleedings. Men above 40 years and persons with severe concomitant disease are specially at risk. The prognosis is rather good, mortality from bleeding being 10%. Surgery should not be undertaken unless all conservative measures, including vasopressin infusion and even Sengstaken-Blakemore tube have been applied. The typical history, a hiatal hernia and alcohol intake are frequently missing. Neither studies of gastric acid secretion nor esophageal manometry disclosed new pathogenic aspects.