To date, there is limited research investigating physical activity levels during a sport education season in high school physical education settings and how these are affected by ability levels. The aim of this study was to investigate (1) how students' game play in basketball would improve during a sport education season as a function of ability level, and (2) how students' MVPA levels differ as a function of game play ability. One class with 21 high school students (aged 16-18) participated in a 14-day sport education basketball season. Prior to and upon completion of the season, students' 3v3 basketball game play performance was assessed. Three mixed ability teams were composed with an equal gender distribution. The System of Observing Fitness Instruction Time (SOFIT) was used to collect students' MVPA during the season. Repeated measures ANOVA detected a significant improvement in game play ability from 52% (range: 28%-68%) to 84% (range: 60%-100%) for high-as well as low-ability students, p < .001. High-ability students engaged in MVPA for 65% during team practice and 49% during game play. Low-ability students had consistently lower MVPA values than high-ability students (41% vs 55%), p <.01, with 56% of MVPA during team practice and 34% during game play. All students spent more than 40% of team practice and game play in vigorous physical activity. We concluded that both high-and low-ability high school students improved their game play and their ability level affected MVPA levels during the sport education basketball season. High-ability students met the 50% MVPA benchmark during team practice and game play, whereas low-ability students only met this guideline during team practice.