en فیزیوتراپی Physiotherapy پژوهشي Research <strong>Background and Objectives:</strong> Forgotten Joint Score-12 is a useful questionnaire to evaluate the level of joint awareness and patients&rsquo; ability to forget the involved joint. The objective of the present study was to obtain a tool to evaluate the level of joint awareness for use in Persian-speaking patients following anterior cruciate ligament reconstruction.<br> <strong>Methods: </strong>The present study was a methodological study in the field of psychometrics, in which after translation and cross-cultural adaptation of the FJS-12 questionnaire according to the ISPOR method, to examine its validity, the questionnaire was given to 114 participants who had passed between 1 and 3 years of their anterior cruciate ligament reconstruction. To evaluate reliability, participants were asked to complete and resubmit the questionnaire after a week. In this study, the intraclass correlation coefficient (ICC) was used to analyze the repeatability of the questionnaire and measure Cronbach&rsquo;s alpha internal consistency. Structural validity was performed by calculating the correlation between the FJS-12 questionnaire and Western Ontario McMaster Osteoarthritis (WOMAC) and Knee Osteoarthritis Outcome Score (KOOS) questionnaires using Spearman&rsquo;s correlation coefficient. The level of ceiling and floor effect of the questionnaire was also assessed.<br> <strong>Results:</strong> Internal consistency and data repeatability were excellent for FJS-12 (Cronbach&rsquo;s &alpha;=0.950 and ICC=0.845, respectively). In examining the validity, a weak to moderate correlation was obtained between the score of the FJS-12 questionnaire and the scores of the subscales of WOMAC (r=0.34) and KOOS (r=0.34). Also, a moderate correlation was obtained between the score of the FJS-12 questionnaire and the first question of the subscale of quality of life in the KOOS questionnaire (r=0.46), which indicates the validity of the average structure of the questionnaire. The floor (4.45%) and ceiling (3.50%) effect was low.<br> <strong>Conclusion: </strong>According to the results of this study, the Persian version of the FJS-12 questionnaire can be used by Persian speakers. Also, this questionnaire is a reliable and valid tool to evaluate the level of joint awareness in individuals following anterior cruciate ligament reconstruction. Cross-cultural Adaptation, Validity, Reliability, Awareness, Anterior Cruciate Ligament Reconstruction 0 0 http://fdj.iums.ac.ir/browse.php?a_code=A-10-173-1&slc_lang=en&sid=1 Elnaz Momeni elnazmomeni70@gmail.com 10031947532846002316 10031947532846002316 No Department of Physiotherapy, Rehabilitation Research Center, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran. Soheil Mansour Sohani mansorsohani.s@iums.ac.ir 10031947532846002317 10031947532846002317 Yes Department of Physiotherapy, Rehabilitation Research Center, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran. Shohreh Nourizadeh Dehkordi noorizadeh.sh@iums.ac.ir 10031947532846002318 10031947532846002318 No Department of Physiotherapy, Rehabilitation Research Center, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran. Ali Amiri amiri.a@iums.ac.ir 10031947532846002319 10031947532846002319 No Department of Physiotherapy, Rehabilitation Research Center, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran. Malek Amini amini.m@iums.ac.ir 10031947532846002320 10031947532846002320 No Department of Occupational Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.