Objective: Personality disorder is a multi-factorial condition in which workplace stress plays a significant role. This study was undertaken due to scarcity of information regarding the role of workplace stress which can cause personality disorder among nurses. We aimed to evaluate the prevalence of personality disorders in nurses working in different hospital departments and assess factors affecting its onset. Methods: In this cross-sectional study the personality disorders of nurses working in various hospital departments were evaluated based on Minnesota Multiphasic Personality Inventory-۲ (MMPI-۲) test. After the completion of questionnaires, data were entered to MMPI-۲ test’s special software and the final result was interpreted based on the opinion of a clinical psychologist. Finally, multivariate logistic regression model was used to assess the independent effect of the mentioned factors on prevalence of personality disorders in nurses. Results: We gathered data from ۲ groups of participants (n = ۲۰۶). These groups included nurses in emergency departments and nurses in other hospital units. The mean of age was ۳۲.۵ ± ۶.۹ years. Overall, ۵۴.۳% (n = ۳۸) of non-emergency nurses and ۴۵.۷% (n = ۳۲) of emergency nurses showed symptoms of personality disorders respectively. Multivariate logistic regression analysis showed that history of a serious accident or trauma increased the odds of detecting personality disorders up to ۳.۸ times (odds ratio [OR] = ۳.۸۴; ۹۵% CI: ۱.۳۳-۱۱.۰۶; P = ۰.۰۱). In addition, an unpleasant incident in the past year increased it up to ۲.۲ times (OR = ۲.۲۳; ۹۵% CI: ۱.۱۸ – ۴.۲۲; P = ۰.۰۱) in both groups. Conclusion: The present study showed that there was no significant difference between emergency departments and other units of hospitals regarding the prevalence of personality disorders among nurses. Overall, somatization, hysteria, and pollyannaish were the most common personality disorders among the studied population
