The present study reported on the modification of the Basic Psychological Needs in Exercise Scale (Vlachopoulos & Michailidou, 2006) to assess students' psychological need fulfillment in elementary school, middle school, and high school compulsory physical education classes. Data were collected from 817 5th and 6th grade students, 862 middle school students and 844 high school students, boys and girls. The findings supported an a priori correlated 3-factor structure of the Basic Psychological Needs in Physical Education scale (BPN-PE) with strong internal reliability for all three school grade levels. Support was also obtained for the nomological validity of the scale responses. Further, measurement invariance emerged for BPN-PE scores across boys and girls and across students who participated or not in out-of-school sports within each school grade level as well as across all three school grade levels. (Contains 3 tables and 1 figure.)