In a 50-year-old patient who was repeatedly hospitalised on account of melaena and twice operated without finding an ulcer the cause of the haemorrhage was first unknown. In the sixth massive haemorrhage endoscopically was established a haemorrhagic erosive gastritis which underwent a spontaneous retrogression (gastroscopic control). Since the skin test on milk was positive, it was not thought of an allergic gastritis by milk and a provocation test was carried out twice which had a positive result (haemorrhagic erosive gastritis after instillation of milk into the stomach). With the publication of this case the attention shall be turned to the gastric haemorrhage caused by a nutritive allergy as well as to the diagnostic value of the simply producible provocation test.