en Health Health Original Research Original Research <strong>Background: </strong>Patient safety practice reduces the adverse events that may occur in the health care system during procedures, diseases, and diagnoses. Failure and negligence in identifying and resolving health care system errors may result in financial and physical harm.&nbsp; Thus, this study aimed to investigate the psychometric properties of the Patient Measure of Safety in Hospitals (PMOS).<br> &nbsp;&nbsp; <strong>Methods:</strong> This study was conducted on 264 patients in 4 hospitals. The patient measure of safety questionnaire has 44 items and 9 domains. To translate the PMOS questionnaire, standardized forward-backward procedure was used, and a panel of experts assessed the face and content validity of the Persian version. Internal consistency, confirmatory factor analysis (CFA), and test-retest method were used to test the validity and reliability of the instrument. Also, AMOS (version 23) and SPSS (version 16) software were used for data analysis and modeling.<br> &nbsp;&nbsp; <strong>Results: </strong>The average CVI score was 0.85, indicating well results in the Persian context. CVR score was 0.65. The indices of goodness of fit were acceptable for Iranian sample (CFI=0.91, TLI=0.89, RMSEA=0.063, relative/normal Chi-Square Statistic (X²/df)=2.85). All items were significantly loaded on the domains, except the 33rd and 38th items that were related to the eighth domain. Thus, the final Persian version was developed with 8 domains and 42 items. Internal consistency was acceptable for these domains, and test-retest method showed a good reliability (r=0.984).<br> <strong>&nbsp;&nbsp; Conclusions: </strong>The Persian version of PMOS is an appropriate instrument to assess the safety of patients in Persian language communities. Also, PMOS is an optimal tool to identify and avoid preventable errors.<br> &nbsp; Hospital, Patient, Safety, Validity, Reliability, Statistical model 443 448 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-3993-1&slc_lang=en&sid=1 Fatemeh Sarvi f.sarvi.2000@gmail.com 200319475328460062556 200319475328460062556 No Department of Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran Mohammad Ebrahim Ghaffari ghaffarimohammad67@yahoo.com 200319475328460062557 200319475328460062557 No Department of Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran Mostafa Eghbalian mostafab.s1992@gmail.com 200319475328460062558 200319475328460062558 No Department of Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran Mahmoud Khodadost . khodadoost@gmail.com 200319475328460062559 200319475328460062559 No Department of Epidemiology, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran Iraj Mohammadfam Mohammadfam@umsha.ac.ir 200319475328460062560 200319475328460062560 No Departments of Occupational Hygiene, Hamadan Medical Science University, Hamadan, Iran Mojtaba Khazaei Khazaeimojtaba@yahoo.com 200319475328460062561 200319475328460062561 No Department of Neurology, Hamadan University of Medical Sciences, Hamadan, IranModeling of Noncommunicable Diseases Research Center, Hamadan University of Medical Sciences, Hamadan, Iran Ali Reza Soltanian soltanian@umsha.ac.ir 200319475328460062562 200319475328460062562 Yes Modeling of Noncommunicable Diseases Research Center, Hamadan University of Medical Sciences, Hamadan, Iran