Two cases of acute hemorrhagic gastric necrosis are presented. The first patient was a 62 yr old man with a past history of chronic gastritis, Parkinson's disease and dementia. The second case was a 25 yr old woman with recent abuse of oral analgesic agents. Both presented with an acute abdomen and peritonitis, and underwent urgent gastrectomy for gastric necrosis with perforation. The first patient died, whereas the second recovered. Histology of the gastrectomy specimens showed severe hemorrhagic transmural gastric necrosis with minimal inflammatory changes. Only occasional Gram positive rods were seen in case 1, and microbiological cultures were negative. The etiology of the gastric necrosis in these 2 cases is unclear.