Background: Experience in non-school contexts can shape and reshape students' motivation and mediate their learning in school. Outside-school physical activity may provide students with an extensive cognitive and affective foundation and influence their motivation in physical education. Although a trans-contextual effect of physical education has been explored, very little empirical research has examined the impact from outside-school context to physical education. Aims: Using self-determination theory and a hierarchical model of motivation, this study was designed to examine the association between participation in organized outside-school physical activity programmes and self-determination process in physical education. Sample: Participants included 545 9th graders (305 males and 240 females, age range = 14-16 years, mean age = 14.66 years) enrolled in required physical education classes in three suburban high schools in a large Midwest metropolitan area in the United States. Methods: Self-determination variables were measured using relevant instruments, and information on organized outside-school physical activity experiences was gathered in a survey. Structural equation modelling analyses were conducted. Results: Students who participated in organized outside-school physical activity programmes displayed overall higher motivation; however, the strength of associations among the self-determination variables (i.e., pathways from perceived autonomy support to relatedness, from autonomy to competence, and from self-determined motivation to in-class physical activity engagement) was stronger for their non-participant counterparts. Conclusion: There are dynamic relationships between participation in organized outside-school physical activity programmes and self-determination process in physical education. Physical educators need to identify, appreciate, and instructionally address individual students' differences during teaching and learning.