Introduction: The effect of diabetes on psychological well-being (PWB) is a concern for the development of medical care in diabetes management. There are few studies have simultaneously evaluated the impacts of related factors in PWB among patients with type 2 diabetes. Method: This cross-sectional study was conducted on 183 male and 317 female patients with diabetes who had been registered in healthcare centers in Behbahan from November 2018 until April 2019. The patients' well-being status, medications, diet, and physical activity (PA) adherances were measured using validated questionnaires. Result: The mean age of the participants was 52.18 +/- 10.29 years. The total mean (SD) score of PWB was 87.40 +/- 9.945. In addition, the results of univariate and multivariate analyses showed that the level of adherence to medication had a significant or close-to significant relationship with PWB score (p < 0.001 and p = 0.082, respectively). The results of univariate and multivariate analyses also indicated that adherence to diet was significantly associated with PWB score (p < 0.001 and p < 0.001, respectively). However, there were no significant differences among PA levels regarding the PWB score (p = 0.087). The results showed that glycemic control was significantly correlated to PWB score (p < 0.001). Conclusion: Despite the wide variety of relating factors to PWB, adherence to the diet and medication could be added to diabetic guidelines to improve glycemic management and well-being. (c) 2021 Elsevier B.V. All rights reserved.