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Background and Objective: Irritable bowel syndrome (IBS) is a disturbance of colonic function characterized by abdominal pain or discomfort, bloating and abnormal bowel function, resulting in episodes of chronic diarrhea, chronic constipation, or both in alternation. It affects approximately 3 to 20 percent of the population. The aim of this study was to investigate the prevalence of Irritable bowel syndrome among the high school pupile in Gorgan, in North of Iran. Materials and Methods: In this descriptive-analytical cross sectional study, data was collected by clustering, quota and randomized sampling. 1080, 15-19 years old male and female high school pupiles, residing in Gorgan participated in the survey during 2007. The data collection tool was a demographic questionnaire and standard Rome-II criteria. Results: 1063 pupiles completed the questionnaire. The Irritable bowel syndrome prevalence according to Rome-II was 5.7%. The relation between ethnicity and Irritable bowel syndrome was significant (P<0.05). The rate of Irritable bowel syndrome was higher among the Turkmen students. There was no significant relation between Irritable bowel syndrome prevalence with gender, age and family income. Conclusion: This study showed that irritable bowel syndrome prevalence in this area is nearly similar to that reported in national studies in western Iran as well as with Asian countries.