We investigated the eradication and recurrence rate of Helicobacter pylori-infected gastric ulcer patients by combination therapies. Eighty-six H. pylori-positive gastric ulcer patients were assigned randomly to one of seven groups: I, omeprazole 20 mg (n = 9); II, lansoprazole (LPZ) 30 mg (n = 16); III, LPZ 30 mg plus plaunotol 480 mg (n = 13); IV, LPZ 30 mg plus ecabet sodium 2 g (n = 11); V, LPZ 30 mg plus clarithromycin 600 mg (the first 2 weeks; n = 11); VI, LPZ 30 mg plus plaunotol 480 mg plus clarithromycin 600 mg (the first 2 weeks; n = 13); and VII, LPZ 30 mg plus ecabet sodium 2 g plus amoxicillin 1,500 mg (the first 2 weeks; n = 13). All therapy was for 8 weeks except where otherwise noted. H. pylori eradication rates as diagnosed by culture, histology, urease test, and [13C]urea breath test 4 weeks after stopping therapy were 0, 0, 8, 45, 6, 46, and 62%, respectively, in groups I-VII. No patient achieving H. pylori eradication suffered recurrence. The combination therapies with proton pump inhibitors in addition to antibiotics and antiulcer agents are safe and effective in H. pylori eradication.