To assess the effects of the mucoprotective drug sofalcone, which has direct and indirect effects on Helicobacter pylori in vitro, the eradication rate, adverse effects, and the quality of healing peptic ulcers were evaluated. Each study patient was given 500 mg t.i.d. amoxicillin and 200 mg t.i.d. clarithromycin. In addition, three different treatment regimens were compared: a standard dose (20 mg q.d.) of the proton pump inhibitor omeprazole (OAC), a double dose (20 mg b.i.d.) of omeprazole (Ox2AC), and a standard dose of omeprazole and a standard dose (100 mg t.i.d.) of sofalcone (OACS). Thirty-one H. pylori-positive patients were treated with OAC, 37 with Ox2AC, and 41 with OACS therapy. With an intention-to-treat analysis, the eradication rates were 74.2% for OAC, 86.2% for Ox2AC, and 85.0% for OACS therapy. The incidence of side effects was 9.6% for patients given OAC therapy, 86.5% for Ox2AC, and only 7.5% for OACS-treated patients, which was significantly lower than the incidence in the Ox2AC group. High-quality peptic ulcer scars were observed after eradication therapy which included solfacone. Although it is necessary to conduct a randomized double-blind study to obtain definitive conclusions, our results indicate that this novel quadruple eradication therapy with solfacone is an efficacious regimen with a high eradication rate and positive effects on ulcer healing, combined with a low incidence of adverse events.