This study aimed to develop an instrument to identify the motives of youth involvement in sports. The Sports Engagement Motivation Instrument (MPS) is constructed through two phases of research, namely the phasing of the item and the psychometric testing of the instrument. Formulation of questionnaire items was conducted in accordance with the Nominal Group Technique process for youths who are active in sports. A total of 75 items were generated from the questionnaire design phase. Alpha Cronbach's factor analysis and coefficient values were used to test the number of factors and internal reliability of the data. The SPS questionnaire was administered to 582 active youths for factor analysis and instrument reliability. The results of the analysis of the principal components of the MPS questionnaire consisted of 58 items, comprising nine factors, namely Raising Country Name, Health and Fitness, Skill Improvement, Wanting Challenges, Seeking Success, Family Pride, Pride, Emotional Stability and Future Assurance. Factor loadings for each item ranged from 0.40 to 0.74, and reliability (alpha) values ranged from 0.66 to 0.93. The validity of MPS content has been evaluated by seven field experts and has confirmed that MPS has validity of content and can accurately test the motives of youth involvement in sports. The findings of this study indicate that the MPS instrument has high reliability and reliability and can be used in identifying adolescents' involvement in sports.