Abstract: Aim of the work: This study was designed to detect mutation in P53 in cases of non-neoplastic Helicobacter Pylori (H. Pylori) gastritis. Method: 55 cases of chronic H. Pylori gastritis were selected and we used immunohistochemical technique to detect P53 expression and compared it with the five parameters in Sydney system (gastric atrophy, intestinal metaplasia, chronicity, and activity and H. Pylori infection). Results: Active chronic gastritis was found in 21.8% of cases, gastric atrophy was detected in 41.8%, and intestinal metaplasia in 74.5% of cases. There was a statistically significant correlation between P53 expression and neutrophilic infiltration (p≤0.005). There was a strong correlation between P53 expression and H. Pylori infection in all the studied cases (p> 0.02). Conclusion: Neutrophil infiltration and chronic gastritis are considered a step in the processes of carcinogenesis through P53 mutation in H. Pylori chronic gastritis.