Background and purpose: Hemodialysis patients experience high levels of psychological stress. This study has been conducted to determine the effect of Benson relaxation on stress among hemodialysis patients. Materials and methods: This clinical trial was conducted in 2011. Eighty hemodialysis patients from Imam Khomeini and Fatemeh Zahra Educational Hospitals in Sari were randomly divided into two groups of 40 (intervention and control). The intervention group was trained with Benson relaxation methods using video tape for 15 minutes. The training sessions were held twice a day during one month, following primary training by the researcher. Demographic data was collected and hemodialysis stress scale questionnaire (HSS-Baldree 1982) was completed before and one month after the intervention. The data was analyzed by t-test, Chi-square and covariate analysis in SPSS18. Results: The mean scores of stress in case group, before the intervention, was 64.75 ± 18.17 which reduced to 36.2 ± 9.47 after the intervention. The mean scores of stress among the participants showed significant difference pre and post-intervention in the case group (P<0.001). However, this difference was not significant in the control group. Conclusion: Performing Benson relaxation which bares low cost could improve the living conditions of hemodialysis patients and also prevents associated psychological problems. Moreover, this method could improve and prevent psychological problems in other chronic patients.