The increase of cross-cultural studies and intervention programs, based on the self-determination theory, highlights the urge for validated scales to ensure high-quality research, particularly in the domain of physical education. The present study aimed at evaluating the psychometric properties and measurement invariance of the revised Perceived Locus of Causality Scale (PLOC-R) in physical education and the Behavioral Regulation in Exercise Questionnaire (BREQ-II) during leisure-time translations from English into German and French among youth. Data obtained from 1808 Luxemburgish students supported the five-factor structure of the translated PLOC-R as well as for the BREQ-II and showed good internal reliability as well as concurrent, discriminant, and nomological validity. Measurement invariance analyses across the two languages revealed configural, metric, and partial scalar invariance for both questionnaires. The findings provide promising evidence for the reliability and validity of the translated PLOC-R and BREQ-II and support their use in cross-cultural and physical activity–related motivational research.