Morphological data on the biopsies obtained from the antral gastric mucosa of 150 chronic gastritis and gastroduodenitis patients provided grounds for recognition of 3 degrees of gastritis activity. Helicobacter pylori (CP) occurred in the antral gastric portion in 100% of the cases. CP presence and mucosa contamination, plasmocytic infiltration, dystrophic changes in the surface and glandular epithelium were found to correlate. Administration of ampiox in a daily dose of 1.0 g for 10 days resulted in a rapid attenuation of painful and dyspepsia syndromes which ceased on treatment day 7. Endoscopically and morphologically, there were more rapid epithelialization of the erosions and inhibited activity of gastritis compared to the control group. In biopsies obtained on treatment week 3-4 CP was not registered in 67% of cases or was present in much less amounts. The control subjects manifested CP universally, the morphological positive trend was unremarkable.