en تخصصي Special پژوهشي Research <strong>Objective:</strong> Diabetes mellitus is a chronic illness and adherence to medications is vital to manage the illness. The purpose of this study was to examine the prediction of medication adherence based on personality factors in a group of individuals with type 2 diabetes in Yasuj.<br> <strong>Materials and Methods</strong><strong>:</strong> One hundred twenty individuals with type 2 diabetes who visited health centers were selected for this study through convenience sampling. The participants completed the NEO-Five Factor Inventory and Medication Adherence Rating Scale (MARS). The data were analyzed by mean, standard deviation, and multiple regression analysis using SPSS software.<br> <strong>Results:</strong> The results showed that among the big-five personality factors, only neuroticisms significantly predicted adherence to medications (&beta;= -0.31, <em>P</em>-value< 0.003). Furthermore, the model explained only 19% of the variance in medication adherence (R²= 0.19, <em>P</em>-value< 0.01).<br> <strong>Conclusion</strong><strong>:</strong> This study indicated that a large proportion of patients with type 2 diabetes did not adhere to their medications. This study highlighted that the personality trait of neuroticism was important in predicting medication adherence in patients with type 2 diabetes.<br> <br> &nbsp; Diabetes mellitus, Personality, Neuroticism, Social support 113 119 http://ijdo.ssu.ac.ir/browse.php?a_code=A-10-30-281&slc_lang=en&sid=1 Abdulaziz Aflakseir 0000-0002-6926-363X Yes Associate Professor, Department of Psychology, School of Education and Psychology, University of Shiraz, Shiraz, Iran Farzad Nikroo 0000-0002-3500-156X No MA Student, Department of Psychology, School of Education and Psychology, University of Shiraz, Shiraz, Iran Javad Mollazade 0000-0001-6193-8906 No Associate Professor, Department of Psychology, School of Education and Psychology, University of Shiraz, Shiraz, Iran