Background and Aims. Helicobacter pylori (H. pylori) is one of the most common chronic infections in patients with gastrointestinal disorders. Recent reports suggested that H. pylori might have high prevalence among patients with diabetes. This study aimed to determine and compare frequency of H. pylori infection in type 2 diabetes mellitus (T2DM) and non-diabetic patients. In addition to, evaluating the relationship between serum oxidized low density lipoprotein (Ox-LDL) levels in T2DM and non-diabetic patients with H pylori infection. Methods. This study was conducted in 100 patients presented with history of epigastric discomfort for more than one month; 50 patients with T2DM and 50 non-diabetics. Anti-H. pylori IgG using ELISA, fasting and postprandial glucose level, glycated hemoglobin (HbA1c) and body mass index (BMI) was calculated. Serum Ox-LDL was measured using competitive sandwich enzyme immunoassay for patients and control subject. Results. Rates of H. pylori infection of T2DM and non-diabetic were 66% and 58%, respectively, (p=0.001). H. pylori IgG antibody was not correlated with HbA1c either in T2DM (p =0.06) or non-diabetic (p= 0.25). Serum Ox-LDL level in type 2 diabetes with positive H. pylori infection showed a significant difference compared to diabetics with both negative H. pylori infection and in non-diabetics with positive H. pylori infection (p=0.001). No correlation between Ox-LDL concentration and HbA1c in T2DM patients infected with H. pylori was observed (r = 0.07, p=0.69) Conclusions. Infection H. pylori in T2DM was higher compared to non-diabetic population and appears not to be associated with glycemic control; T2DM seems to be associated with increased oxidative stress in H. pylori infection. Increased Ox-LDL levels suggest the mechanistic link between H. pylori infection combined with diabetes and increased generation of ROS and could play as an important image for high risk to atherosclerosis.