Objective: The study aimed to ranking the challenges of accreditation standards implementation in private and public hospitals. Methodology: The method of data collection was descriptive research of field studies branch. Statistical population included the managing director, manager, matron and head of Quality Control (accreditation) of public and private hospital of Tehran. For collecting data, a questionnaire was designed in 39 items based on reviewing of literature and previous scale. Content and face validity of this questionnaire was considered and confirmed in separately stages; also, reliability of this questionnaire investigated through Cronbach’s alpha and for whole dimensions were higher than 0.7. In final, for data analysis and testing assumptions, exploratory factor analysis and Friedman test has been administered by using SPSS-20. Results: result of exploratory factor analysis showed that challenges of accreditation standard implementation were classified in 9 aspects and explained 72.4% variance of this variable. These 9 factors in order to priority are encouraging drivers; perception of accreditation standards; financial resources; quality improvement; management knowledge, skills and commitment; support of regulatory initiatives; standard & surveying development; human resources and determining macro policies and procedures. Also finding showed that there are differences between the ranking of these challenges in public and private hospitals. Conclusion: the results of the study showed that the challenges which have the highest rank are ones of the main obstacles of implementation of accreditation in hospitals and more attention should be given to them.
