en فیزیوتراپی Physiotherapy پژوهشي Research <strong>Background and Objectives</strong>: The Kerlan-Jobe Orthopedic Clinic Shoulder and Elbow Score (KJOC-SES) is a reliable and sensitive tool used to measure the performance and function in overhead athletes with shoulder and elbow injuries. This study aimed to culturally adapt and validate the KJOC-SES questionnaire in the Persian language.&nbsp;<br> <strong>Materials and Methods</strong>: A total number of 341 healthy competitive overhead athletes took part in this cross-sectional study and completed the KJOC-SES questionnaire. To assess the reliability of the KJOC-SES, 41 professional volleyball players filled out the questionnaire at the baseline and after a 4-week interval, during the off-season. Also, we compared the scores of KJOC-SES with those of the sports/performing arts module of disabilities of the arm, shoulder, and hand and the 12-item short-form health survey to test the construct validity. Moreover, we investigated the internal consistency and the concurrent validity of all measures.<br> <strong>Results</strong>: The KJOC-SES was correlated with the sports/performing arts module of the disabilities of the arm, shoulder, and hand (r=&minus;0.559, P<0.001), and the 12-item short-form health survey (r=&minus;0.505, P<0.001). The KJOC-SES had an excellent internal consistency (the Cronbach alpha=0.92). Also, the intra-class correlation coefficients of test-retest reliability for the 10 items of KJOC-SES were excellent (ICC=0.82, P<0.001). The new score correctly stratified overhead athletes by the injury category (P<0.001).<br> <strong>Conclusion</strong>: The KJOC-SES is a valid and reliable tool for assessing the shoulder and elbow injuries in Iranian overhead athletes.<br> &nbsp; Kerlan–Jobe, Shoulder, Elbow, Cross-cultural adaptation, Validation, Persian language 35 44 http://fdj.iums.ac.ir/browse.php?a_code=A-10-78-4&slc_lang=en&sid=1 Samineh Moarref moarref.s@gmail.com 10031947532846001898 10031947532846001898 No Department of Physiotherapy, School of Rehabilitation, Iran University of Medical Sciences, Tehran, Iran. Shohreh Noorizadeh Dehkordi noorizadeh.sh@iums.ac.ir 10031947532846001899 10031947532846001899 Yes Department of Physiotherapy, School of Rehabilitation, Iran University of Medical Sciences, Tehran, Iran. Mohammad Akbari Akbari.mo@iums.ac.ir 10031947532846001900 10031947532846001900 No Department of Physiotherapy, School of Rehabilitation, Iran University of Medical Sciences, Tehran, Iran. Najmeh Sedighimehr najmehsedighimehr@gmail.com 10031947532846001901 10031947532846001901 No Department of Physiotherapy, School of Rehabilitation, Shiraz University of Medical Sciences, Shiraz, Iran.