It is well recognized that diabetes mellitus develop a variety of complications during the course of disease, such as diabetic triopathy. After one to two decades of overt disease, approximately 30-60% of diabetics develop clinical signs of visceral autonomic neuropathy. Peptic ulcer patients with diabetes mellitus have these complicated backgrounds. The prevalence of peptic ulcer disease in asymptomatic diabetic patients was reported as 5.3% to 7.3% in Japan. We evaluated the efficacy of Helicobacter pylori eradication therapy in peptic ulcer patients with non-insulin dependent diabetes mellitus. The cure rate of peptic ulcer and gastritis score at 8 weeks after eradication therapy is similar with non-diabetic patients. Our data suggests that the eradication of Helicobacter pylori becomes a first therapy in peptic ulcer patients with non-insulin dependent diabetes mellitus.