Psychiatric morbidity is frequent among outpatients with Irritable Bowel Syndrome (IBS) attending gastroenterology clinics. The lifetime prevalence of major depressive and anxiety disorders in IBS patients are up to 76% and 54% respectively. The point prevalence of Major depressive disorder and Anxiety disorders in IBS patients are ranged 9.6 to 54% and from 11.1 to 52.4% respectively. IBS is not usually life-threatening but it has a significant impact on quality of life. So, screening for psychiatric disorders in IBS patients attending Gastroenterology clinics is worthwhile. The objective of this study was to evaluate psychiatric morbidity among the patients with IBS. This cross sectional comparative study was conducted in the Department of Psychiatry, Sylhet MAG Osmani Medical College Hospital, Sylhet, Bangladesh during the period from January 2012 to June 2012. Inclusion criteria were patients of irritable bowel syndrome fulfilling the Rome-III criteria, age between 18 to 60 years irrespective of sex. Patients with any red flag sign, serious cognitive impairment such as dementia, schizophrenia, mania, delusional disorder, prior history of abdominal surgery and other chronic diseases were excluded. One hundred and ten patients with IBS were selected according to inclusion and exclusion criteria and categorized as IBS group. Another 110 age and sex matched subjects were selected as control group. The mean±SD age of the patients was 34.3±12.2 years which was almost identical to control group (p=0.820). Most of the patients (66.4%) were below the age of 40 years. There were 64 (58.2%) male and 46 (41.8%) female which was similar to control group (p=0.643). Psychiatric co-morbidity was most frequent in IBS patients (56.4%) as compared to control group (16.4%) p value <0.001. The most common psychiatric disorders were Anxiety disorders (22.7%), followed by major depressive disorder (19.1%) and somatization disorder (14.5%). The results of this study suggest that a significant number of patients with IBS suffer from psychiatric disorders than control, which are similar to the IBS group in age and gender.