Introduction: Acquiring clinical skills in medical internship needs to design appropriate educational planning. The aim of this study was to evaluate the psychometric adequacy of the preparedness for Internship Questionnaire in 2016.
Methods:  This cross - sectional study has been done on medical interns through sampling method in Shiraz university of medical sciences. The Initial instrument was 48-item questionnaire with Rubric score adopted from previous studies and translated to Persian after developer’s permit.   Face and content validity of the instrument were assessed by 10 students and specialists. Construct validity was assessed by Explanatory factor analysis and Reliability of the scale was determined by alpha cronbach coefficient and with the test-retest method. Data were analyzed by AMOS and SPSS.
Results: By using explanatory factor analysis, 47 questions retained in the questionnaire and classified into seven factors .These factors capable to predict 65% of the properties of the total questionnaire. The factors based on their concepts including: Practical tasks, clinical skills and stress control, communication skills, carry out basic procedures, Self- learning and task management. Spearman correlation coefficient for this study was (ρ=.875), and the alpha Cronbach was (α=.935). Results of the study approved based on the results of confirmatory factor analysis.
Conclusion: The results of this study indicated the strength of the factor structure and reliability of the instrument of preparedness for internship and can assesses the preparedness for internship in universities and other educational institutes.