Background: Gastritis can be caused by many factors, one of them is drugs, and among these drugs is dexamethasone that has many uses in medicine. Dexamethasone prevent synthesis of gastric mucous barrier by surface epithelial cells, so the stomach wall will be injured by digestive enzymes and stomach HCl. Treatment of gastritis can be done by antisecretory drugs like H₂ receptors blocker as ranitidine or by  drugs that stimulate prostaglandins synthesize by surface epithelial cells of gastric mucosa  to form the mucous barrier like rebamipide.
Aim of the work: Comparison between ranitidine and rebamipide to detect which mechanism is better in gastric mucosal protection after dexamethasone administration.
Material and methods: Twenty male albino rats were included in this study, they were divided into four groups, control group, dexamethasone administrated group, dexamethasone and ranitidine administrated group, dexamethasone and rebamipide administrated group, each group contained five rats.
The examined samples were stained with hematoxylin & eosin stain, PAS & Alcian blue stains and TdT reaction, all of the results were statistically analyzed.
Results: The result showed improvement of the gastric mucosa by using both of ranitidine and rebamipide as protective agents against injury induced by dexamethasone but the improvement was better in the group that was administrated rebamipide as indicated by better number of healthy cells, low numbers of damaged cells and better formed mucous barrier.Conclusion: The drug that stimulates mucous barrier formation is better than antisecretory drug in gastric mucosa protection.