ABSTRACT: Introduction & Objective : Irritable bowel syndrom (IBS) is the most common functional bowel disorder which both the bowel and the brain are involved in this syndrom. Combined medical - relaxational therapy has been suggestd to decrease anxiety and relieve symptoms, make better feeling of self health and improve the quality of life in these patients.This study was designed to determine the effects of Benson relaxation technique on anxiety level and quality of life of patients with irritable bowel syndrome. Materials & Methods: In a clinical trial, 30 patients with irritable bowel syndrom were selected and randomly placed into two groups: case and control.The control group was treated by only usual medical therapy but the case group was treated by combined medical - relaxational therapy. The two groups continued therapy for three months. The anxiety of patients was measured by Spielberger test [State& Trait Anxiety Inventory (STAI)]. The quality of life of patients with regard to irritable bowel syndrome, was measured by BS-QOI with subscales 8, before intervention,1 week and 3 months after intervention in both groups. The collected data were analyzed by descriptive and Mann-whitney, repeated measurement tast and chi-square statistical methods. Results: State and trait anxiety mean of the case and control groups two weeks before and one week after intervention didn’t show any significant differences. But after three months the results showed a significant difference between the two groups(p<0.05). There wasn’t significant difference in scales of quality of life before intervention. One week after the intervention, differences of both group in four scales of dysphoria, health worry, social reaction and relationship were meaningful and the function of case group was more undesirable than that of the control group.Three months after completing the process, there wasn’t a meaningful increase in sex function in case group in comparison with the control group but there was a significant recovery in the case group in other performance scales (p<0.001). The quality of life of patients in control group compared to case group decreased or did not change significantly after 3 months. Conclusion: Performing Benson relaxation therapy is effective in reducing anxiety level coinciding with improvement quality 0f life therefore relaxation therapy can be recommended as an effective care program.