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Background and Objective: Irritable bowel syndrome (IBS) is the most prevalent gastrointestinal disorder and is one the common conditions seen by gastroenterologists in their daily practice. This study was done to determine the prevalence of celiac disease in patients with irritable bowel syndrome in Ardabil-Iran. Materials and Methods: This descriptive study was conducted on 105 patients with IBS whome referred to the gastroenterology unit in Ardabil-Iran during 2009-10. Serum IgA anti tTG were measured all patients with positive for antibodies against tTG were candidated for upper endoscopy and biopsy. Data were analyzed using SPSS-16, t-test, Chi-Square and Fisher’s exact tests. Results: The average age of IBS subjects were 31.4±10.14 years (range 16-63 years). Celiac disease was diagnosed in 14 subjects (13.5%). The celiac patient age were 22-55 years with mean of 34.93±9.47. Among celiac afflicted patients IBS type D and M observed among 10 and 4 patients, respectivley. Celiac affected female constituted 12 (85.7%) of all patients (P<0.05). 10 of these patients were IBS-D and 4 with IBS-M. From 14 celiac patient 4 (28.57%) were family related, but this rate among IBS patient was 3.3%, this difference was significant (P<0.05). Conclusion: This study showed that the prevalence of celiac in patients with IBS is found to be 13.5% which seem is more than ther studies in other parts of Iran.