Chronic Helicobacter (H.) pylori infection is an etiological factor related to gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The expression of bcl-2 protein significantly decreases as the grade of MALT lymphoma advances. The aim of this study was to evaluate bcl-2 expression in inflammatory cells in lamina propria in gastric biopsy samples collected from two groups of patients with chronic gastritis divided on the basis of the success or failure of H. pylori eradication. Sixty-five patients with chronic gastritis were divided into two groups of 45 and 20 patients according to their therapeutic response. The gastric mucosa samples were analyzed histologically in both groups of patients before and after standard therapy (for eradicated, after one therapeutic cycle; and for non-eradicated, after three therapeutic cycles) for H. pylori density, urease activity and bcl-2 expression. In the eradicated group of patients, H. pylori eradication was accompanied by significantly lower grades of bacterial colonization and lower urease activity in the corpus and antrum. Bcl-2 expression in inflammatory cells showed no statistically significant changes in either patient group at either location. There was no between-group difference in bcl-2 expression either. In conclusion, persistent long-lasting H. pylori infection is associated with higher grades of bacterial colonization and higher urease activity but not with bcl-2 expression in inflammatory cells.