This study reviews the cases of patients examined repeatedly by endoscopy with biopsies for over one year after eradication of H. pylori, measured according to the Sydney system. For 81 patients in whom H. pylori was successfully eradicated, the endoscopic features of edema, erythema, friability, exudate, erosion and rugal hypertrophy disappeared or diminished at 1-3 months after the therapy and endoscopic features of nodularity disappeared or diminished 12-15 months after the therapy. In these H. pylori-eradicated patients, the histological findings of inflammation and activity regressed 1-3 months after therapy, and atrophy and intestinal metaplasia regressed in 22(27%) and 28(35%) of the 81 patients examined 12-15 months after therapy. Regression of the atrophic pattern was observed in 38(47%) of these H. pylori-eradicated patients. In some H. pylori-eradicated patients, the regressions of atrophy and intestinal metaplasia were observed over one year after H. pylori eradication therapy. Inflammation and activity in the histological findings were related to the endoscopic findings of edema, erythema, friability, exudate, erosion and rugal hypertrophy.