Background:Helicobacter pyloriinfection is the most common cause of peptic ulcer disease. However, the prevalence rates of non-helicobacter pylori idiopathic peptic ulcers have increased over the past few years. This study aims to compare the characteristics ofHelicobacter pylori-positive with idiopathic duodenal ulcers.Methods:A cross-sectional cohort study was conducted on 950 patients which were excluded from the analysis process duo to the concomitant presence of gastric ulcer, malignancy, Zollinger Ellison syndrome, Crohn's disease, esophageal varices, history of taking anti-Helicobacter pylori therapy, and history of taking NSAID or aspirin. Eventually, 647 subjects were enrolled for the analysis process. In this case, these subjects were divided into two groups: (I)Helicobacter pylori-positive ulcer group and (II)Helicobacter pylori-negative and non-NSAID (idiopathic) ulcer group.Results:The findings showed that 417 patients (64.5%) had duodenal ulcers induced byHelicobacter pylori, and 111 patients (17.1%) hadHelicobacter pylori-negative and non-NSAID ulcers. The mean ages of patients inHelicobacter pylori-positive and idiopathic ulcer groups were 39±15 and 42±17, respectively. In this case, 33 patients (29.7%) with idiopathic ulcers and 56 patients (25.1%) withHelicobacter pylori-positive ulcers had upper gastrointestinal bleeding. Also, 22 patients (21%) with idiopathic ulcers and 31 patients (16.5%) withHelicobacter pylori-positive ulcers had multiple duodenal ulcersConclusion:The present study demonstrated that the idiopathic ulcers included 17.1% of duodenal ulcers. Also, it was concluded that patients with idiopathic ulcers were predominantly male with an age range older than the other group. In addition, patients in this group had more ulcers.