The aim of the present study was to determine the efficacy of a new combination regimen including antioxidant, proton pump inhibitor, and antibiotics against Helicobacter pylori and to document the changes of oxidative stress and cytokines involved in H. pylori-associated gastritis. From each of 57 patients with endoscopically diagnosed gastric and/or duodenal ulcers associated with H. pylori infection, five gastric antral biopsy specimens were taken for the diagnosis of H. pylori and for experimental measures. The patients were then treated either with lansoprozole 30 mg + amoxicillin 1.5 g (LA group; 21 patients) or lansoprazole 30 mg + amoxicillin 1.5 g + rebamipide 300 mg (LAM group; 36 patients) for two weeks. Four weeks after the initiation of treatment, the patients were endoscoped again and biopsy specimens were obtained. Mucosal malondialdehyde (MDA) levels; myeloperoxidase (MPO) activities; superoxide dismutase; catalase; glutathione peroxidase; cytokines IL-1, IL-6, TNF-alpha; and chemokines IL-8, GRO-alpha, RANTES (regulated on activation normal T expressed and secreted) were measured. Using paraffin-embedded tissue sections, in situ terminal deoxyribonucleotide transferase (TdT) -mediated dUTP nick end labeling (TUNEL) for apoptosis and immunohistochemical staining for inducible nitric oxide synthase (iNOS) were performed. Two weeks of treatment with the LA regimen resulted in 57.4% eradication rates of H. pylori, whereas two weeks of treatment with the LAM regimen resulted in 75.0% eradication rates. Eradication rates between these two groups were statistically significantly different (P < 0.05). Mucosal MDA levels and MPO activities were significantly lower in the LAM group than the LA group. Mucosal levels of cytokines IL-1, IL-6, and TNF-alpha and of chemokines IL-8, GRO-alpha, and RANTES were all significantly decreased after the treatment of H. pylori, especially in the LAM-treated group. The apoptotic index and iNOS score were significantly reduced after the eradication of H. pylori. The addition of the antioxidative drug rebamipide to the eradication regimen against H. pylori has quantitative and qualitative advantages such as either augmenting the eradication rates of H. pylori or decreasing oxidative stress and cytokines levels generated by H. pylori infection.