Background : The irritable bowel syndrome is one of the common gastrointestinal disorder and according to biopsychosocial model, personality traits play major role in onset, relapse and severity of IBS. The aim of the current research was to determine the personality traits of IBS patients.   
Materials and Methods: In this analytical cross -sectional study, the personality traits of 50 individuals, diagnosed as IBS patients by Gastroenterologist and 50 healthy individuals were compared. The data was gathered by NEO personality inventory (NEO-FFI) and analyzed by multivariate analysis of variance.
Results: The findings of the research showed that patients with IBS, have more neuroticism and less extraversion in comparison with healthy individuals (p <0/05) and there was no significant difference between these two groups in other personality traits (p>0/05).
Conclusion: The results of this research indicated that some personality traits make individuals more vulnerable to IBS and probability of IBS infection could be predicted based on personality traits.