Introduction: Diabetes is among the common diseases in the elderly which results in depression, anxiety, and emotional distress in the elderly and impacts the disease control by the individual. This study was conducted with the aim of exploring the effectiveness of acceptance and commitment therapy (ACT) in the improvement of emotional distress in the elderly with type 2 diabetes. Materials and methods: In this randomized control trial, 80 elderly with type 2 diabetes aged ≥60 years were randomly selected among the individuals visiting Yazd Diabetes Research Center. Then, the patients were randomly divided into two 40 individual groups, ie, the intervention group and the control group. The intervention group underwent group ACT during eight 90-min sessions. The diabetes-related emotional distress questionnaire was completed before the intervention, after the end of the group sessions and 2 months after that. The statistical software SPSS version 21 was used for data analysis. Results: The emotional mean scores in the intervention and control groups were not significantly different before the intervention. However, the mean score of the intervention group was lower than of the control group immediately after the intervention (p=0.02) and 2 months after the intervention (p=0.02). Conclusion: ACT results in the improvement of diabetes-related emotional distress in the intervention group. Considering the effectiveness of ACT, this therapeutic method is recommended to be used for the amelioration of emotional distress in the elderly with type 2 diabetes.