Fifty-four patients (41 men, 13 women), aged 17 to 78 years (mean +/- SD, 48.13 +/- 13.5 years), with endoscopically confirmed healing of their duodenal ulcer after treatment with sucralfate (2 gm BID for 4 to 8 weeks) were recruited for this study. They were started on a 6-month maintenance treatment with sucralfate 1 gm BID. Endoscopy was done at the end of the 6-month period or whenever there was any evidence of ulcer relapse. Helicobacter pylori antral colonization (CLO test) and antral gastritis were estimated from biopsy samples taken before, and at the end of, the healing treatment, as well as at the end of the maintenance treatment. Cumulative relapse rate after 6 months was 15% (8 of 54). No patient discontinued treatment because of side effects. No influence of sucralfate on H pylori antral colonization or antral gastritis was observed after the healing or maintenance treatment. It is concluded that sucralfate 1 gm BID for 6 months is an effective maintenance treatment for duodenal ulcer, but has no beneficial effect on either H pylori antral colonization or antral gastritis.