The abdominal computed tomographic (CT) scans from 61 patients with biopsy-proved Helicobacter (formerly Campylobacter) pylori gastritis were retrospectively reviewed. The CT scans were interpreted on the basis of the original report of the findings at CT examination and without knowledge of the results of biopsy. Of 19 patients (31%) with gastric abnormalities at CT, 14 (74%) had inflammatory changes initially reported as suspicious for gastric malignancy; malignancy was entertained as the primary diagnosis in four of those patients. In five of the 19 abnormal cases (26%), the diagnosis with CT was gastritis. The two major patterns of severe H pylori infection identified were (a) circumferential antral wall thickening and (b) thickening of the posterior gastric wall along the greater curvature, with or without evidence of ulceration. Thickening averaged 1.5-2.0 cm in cases suspicious for malignancy. The majority of abnormalities involved the gastric antrum (68%). No cases demonstrated significant adenopathy, obliteration of fat planes, or invasion of adjacent organs.