Psychometric Properties of Persian Version of the Movement Imagery Questionnaire-3 for Youth The purpose of this study was to evaluate the psychometric properties of the Persian version of the The Movement Imagery Questionnaire-3 for Youth. First, the original version of this inventory was translated into Persian and verified with forward-backward standard method, Then, 220 youth athletes (120 girls, 100 boys) who were engaged in Nahavand sports gyms were selected in randomized cluster sampling method and completed the questionnaire (12 questions). Content validity was evaluated through content validity ratio index (CVR), structural validity measured with confirmatory factor analysis by AMOS. The internal reliability of factors and total reliability of scales were also calculated from Cronbach's alpha. So, we can use this scale as a valid and reliable tool for measuring the ability of imagery in three dimensions, motor imagery, internal visual imagery, and external visual imagery. Key words: Mental Imagery, Visual Imagery, Validity, Reliability, Concurrent Validity, Internal Consistency.