Helicobacter pylori (H. pylori), one of the most common chronic infections, is the main etiologic agent of gastritis, peptic ulcer and gastric cancer. Patients with diabetes mellitus are often affected by chronic infections. Many studies have evaluated the prevalence of H. pylori infection in diabetic patients and the possible role of this condition in their metabolic control. Some studies found a higher prevalence of the infection in diabetic patients and a reduced glycaemic control, while others did not support any correlation between metabolic control and H. pylori infection. There are only a few studies on the eradication rate of H. pylori in diabetic patients. Most of these papers concluded that standard antibiotic therapy allows a significantly lower H. pylori eradication rate in diabetic patients than is observed in control groups. Changes in the microvasculature of the stomach with a possible reduction of antibiotic absorption. The presence of gastroparesis and the frequent use of antibiotics for recurrent bacterial infections with the development of resistant and be some of the mechanisms underlying this phenomenon. Some studies found that H. pylori infection significantly and independently contributed to promoting insulin resistance in a large asymptomatic population. Insulin resistance is the pathophysiologic background of the atherosclerosis and cardiovascular diseases