The prolapse of redundant gastric mucos into duodenal bulb through the pyloric canal was first described by von Schmieden in 1911. Since the Scott's paper was published in 1946. numerous papers have appeared in both theradiological and clinical journals. There has been a difference of opinion concerning the significance of this finding. Some have believed it to be a frequent cause of symptoms related to the uper gastrointestinal tract andhave considered it to be a cause for bleeding. Other observers have stated that in majority of patients demonstrable prolapse of gastric mucosa through the pylorus has little or no clinical significance. During the period from Oct. 1976 to June, 1978, 1774 cases of upper gastrointestinal examination was studied in the Dept. of Radiology, Jenobug National University Hospital. Among these, we detected 83 cases of prolapsed gastric mucosainto the duodenal bulb radiologically and analyzed the relationship of prolapsed gastric mucosa to age, sex,symptoms, radiological findings. fiberscopic findings and combined diseases as followings; 1. In a total of 1774 cases of upper gastrointestinal examination gastric mucosal prolapse into the duodenal buld was 83 cases and itsincidence was 4.7%. 2. The sex distribution was 47 cases (56.6%) in male and 36 cases (43.4%) in female, and thesex ratio was 1.3;1(M:F). 3. The age distribution was 20.5% in 3rd decade, 28.9% in 4th decade and 24.1% in 5th decade. 4. The cases of no abnormal findings except for gastric mucosal prolapse radiologically were 17 cases(20.5%) and the remainders, 66 case (79.5%) were combined with one or more of following in 10 cases (12.0%),ascariasis in 10 cases (12.0%), gastric ulcer in 8 cases (9.6%), diverticulum of duodenum in 4 cases (4.8%), esophageal varix in 4 cases (4.8%), gastric polyp in 2 cases (2.4%) cascade stomach in 39 cases (47.0%) and cholecystopathy in 2 cases (2.4%). Among the 83 cases, fiberscopic examination was performed in 8 cases; 7 cases were gastritis and one case was duodenitis. The gastritis had most frequent relationship to gastric mucosal prolapse. 5. The everyone, of 83 cases of gastric mucosal prolapse complained of one or more gastrointestinal symptoms. 6. The 17 cases which has no abnormal radiological findings except for gastric mucosal prolapse complained of one or more gstrointestinal symptoms as followings; epigastric pain and fullness in 11 cases(64.75), nausea in 8 cases (46.1%), dizziness in 6 cases (35.3%) and experience of hematemesis in 2 cases(11.8%). This was good result of the presence of relationship between clinical symptoms and the prolapse of gastric mucosa into the duodenal bulb.