The aim of this study was to compare the additive effect of rebamipide with that of teprenone in combination with dual therapy on H. pylori eradication. A total of 102 H. pylori-positive gastric ulcer patients were assigned at random to two groups; in addition to dual therapy (amoxicillin 500 mg thrice daily and lansoprazole 30 mg every morning for two weeks), one group received rebamipide 100 mg thrice daily for eight weeks, while the other group received teprenone 50 mg thrice daily for eight weeks. H. pylori diagnosis after treatment was made by [13C]UBT. The ulcer healing rate was 85.7% in the rebamipide group and 79.5% in the teprenone group (P = NS). The eradication rate was 68.4% (95% CI = 54-83%) in the rebamipide group and 47.7% (95% CI = 32-61%) in the teprenone group (P = 0.043) by per-protocol analysis. These findings suggest that the efficacy of dual therapy may be increased by the administration of rebamipide.