A two-year endoscopic follow-up study of 45 gastric ulcer patients was conducted in order to ascertain the relationship between Helicobacter pylori infection, the transformation of ulcer scar patterns, and ulcer relapse during maintenance therapy. Endoscopic findings of gastric ulcer scar patterns, which established the quality of ulcer scars, were classified as follows: Sa, with a central depression, Sb, with a coarse regenerating mucosal pattern up to the center, and Sc, with a fine pattern. The proportion of ulcer relapses was 62% among 29 H. pylori-positive patients and 0% among 16 H. pylori-negative patients. In regard to the relationship between H. pylori infection and scar patterns, 94% of the H. pylori-negative patients displayed Sc scar patterns, while all the H. pylori-positive patients showed various scar patterns, ie, Sa in 38%, Sb in 28%, and Sc in 10%. Ulcer relapses in the H. pylori-positive cases were limited to the Sa and Sb groups (100% and 88%, respectively). In conclusion, our results indicate that H. pylori infection plays an important role in the transformation of the ulcer scar patterns which relate to ulcer relapse.