Introduction: Psychiatric disorders are common in Irritable Bowel Syndrome (IBS) patients. Prevalence of psychiatric disorders is varies in IBS patients in different societies.Objective: To determine the prevalence of psychiatric disorders (anxiety-depression) in IBS patients in Rasht.Materials and Methods: In this cross-sectional study, 256 IBS patients were selected (using criteria of Rome III) and evaluated for psychiatric disorders. In the first phase, subjects were screened by GHQ28. In the second phase, those patients who had scores equal or more than 23 were assessed through semi-structured psychiatric interview. Sociodemographic variables including age, gender, marital status, educational level and occupation, were recorded as well. Pvalues less than 0.05 were considered statistically significant.Results: Among 256 subjects 30 patients (11.7%) had no significant psychiatric symptoms and 226 subjects (83 male, 143 female) suffered from some degrees of psychiatric problems. After performing semi-structured psychiatric interview; 190 subjects (74.2%) had anxiety-depressive problems [89 patients were suffered from pure anxiety disorders, 41 patients suffered from depressive disorders and 60 patients had co-morbid anxiety-depressive disorders].In anxiety disorders; generalized anxiety disorder (53.7%) and in depressive disorders; dysthymia (53.5%) had the most frequencies, 53.7% and 53.5% respectively. In comparisone of anxiety-depressive subjects (190 persons) and normal subjects (66 persons), there was a significant statistical differences between the gender (P=0.019), occupation (P=0.002) and intensity of IBS (P<0.001).Conclusion: Although, further studies are needed to determine the relations of demographic variables and types of IBS with psychiatric disorders, it seems to more attention to the psychiatric disorders of some specific patients suffering from IBS is helpful to their treatment.