Tehran University of Medical Sciences Journal of Medical Ethics and History of Medicine 2008-0387 12 0 2019 10 15 508 508 Leila Amirhajlou Researcher, Department of Medical Education, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Ali Bidari Professor, Department of Emergency Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Fateme Alipour Associate Professor, Department of Ophthalmology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Mehdi Yaseri Associate Professor, Department of Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Samira Vaziri Assistant Professor, Department of Emergency Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Mahdi Rezaie Assistant Professor, Department of Emergency Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Nader Tavakoli Associate Professor, Trauma and Injury Research Center, Iran University of Medical Sciences, Tehran, Iran Davood Farsi Associate Professor, Department of Emergency Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Mohammad Yasinzadeh Assistant Professor, Department of Emergency Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Reza Mosaddegh Assistant Professor, Department of Emergency Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Akram Hashemi Assistant Professor, Department of Medical Ethics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. 2018 11 11 2020 04 05 Professionalism is a core competency in the medical profession. In this paper, we aimed to confirm the validity, reliability and acceptability of the Professionalism Mini-Evaluation Exercise (P-MEX) instrument for the emergency medicine (EM) residency program. Twenty-two EM attending physicians completed 383 P-MEX forms (the Persian version) for 90 EM residents. Construct validity was assessed via structural equation modeling (SEM). The reliability coefficient was estimated by the generalizability theory, and acceptability was assessed using two researcher-made questionnaires to evaluate the perspectives of residents and assessors. There was a consensus among the participants regarding the content of P-MEX. According to the results of SEM, the first implementation of the original model was associated with a moderate fit and high item loadings. The model modified with correlated error variances for two pairs of items showed an appropriate fit. The reliability of P-MEX was 0.81 for 14 occasions. The perception survey indicated high acceptability for P-MEX from the viewpoint of the residents and increasing satisfaction with P-MEX among the assessors over time. According to the results of the research, P-MEX is a reliable, valid, and acceptable instrument for assessing professionalism in EM residents. https://jmehm.tums.ac.ir/index.php/jmehm/article/view/508 https://jmehm.tums.ac.ir/index.php/jmehm/article/download/508/315