Background and Objectives: Being away from the familiar surroundings and family supports, decline in capabilities and skills, and age-related failures can lead to mental problems in the elderly living in nursing homes. This study was conducted with the aim of investigating the effectiveness of spiritual-religious psychotherapy on mental distress in the elderly in nursing homes. Methods: The study population of this semi-experimental study with control group and pretest-posttest, consisted of all elderly living in the nursing home of Bandar Abbas, southern Iran in 2016. Samples (n: 28) were selected by convenience sampling and then randomly divided into two groups, experimental and control. Experimental group received spiritual-religion psychotherapy. Data collection instrument was Depression, Anxiety and Stress Scales. Data analysis was conducted by multivariate analysis of variance in the SPSS version 22. Results: Spiritual-religious psychotherapy had significant effect in improving depression (F=138.47, p<0.05), anxiety (F=34.57, p<0.05), and stress (F=87.30, p<0.05). Conclusion: Spiritual-religious psychotherapy can serve as an effective approach to improve mental distress in the elderly.