A case report is given of a patient with severe upper gastrointestinal bleeding, the source of which could not be localized immediately. Glycylpressin (GP) was applied since bleeding from esophageal varices was suspected. During surgery a gastric ulcer was found penetrating into the pancreas and eroding the splenic artery. A segmental ischemic necrosis of the coecum was found as well, - a complication not yet reported after use of GP. Problems of using GP as a therapeutic agent and especially intestinal necrosis as a complication are discussed. The patient had gastrectomy, splenectomy and hemicolectomy and recovered well.