Physical education focuses on the development of sports skills as well as fitness for health. In Central European countries there has been a shift in these focuses since the fall of Communism to follow internationally-recognised health-related physical activity recommendations, similar to Western European countries. In this study we investigated the extent to which motivation from school physical education transfers to leisure-time physical activity providing autonomy support by three social agents: school (physical education teachers), family and peers. Our study utilised the Aetological Approach (AA), Ecological Model (EM) and the Trans-Contextual Model (TCM) that consists of the Theory of Planned Behaviour (TPB) and the Self-Determination Theory (SDT) to explore how autonomous motivation is transferred between contexts (physical education, leisure-time and current behaviour). Nine-hundred and seventy-four students aged 11–18 (55% girls) participated in our study from four countries: Hungary, United Kingdom, Romania and Slovakia. A prospective research design was employed, and questionnaires were administered at three time points. Using 7-point Likert scales, attitude, usefulness, and affectiveness were measured. Furthermore, subjective norms and perceived behavioural control (PBC) were tested within TPB. Autonomous and controlling motivation were measured within SDT by administering the Behavioural Regulation in Exercise questionnaires (BREQ and BREQ-2). Finally, past physical activity, intention and current physical activity behaviours were tested. Results indicated that perceived autonomy support from family and friends predicted autonomous motivation towards leisure-time physical activity in all four countries. However, teachers’ behaviour in some Eastern European countries did not predict this transfer. In general, in line with previous literature, boys reported more physical activity than girls. A strong influencing factor in the path model was that past behaviour predicted current behaviour, and according to that factor, boys reported being more active than girls.Boys also perceived more support from PE teachers than girls which was likely to have influenced their autonomous motivation in PE, which in turn transferred to leisure time. We discuss these results in the context of theories exploring the role of motivation and social environment on children’s choices related to physical activity. In conclusion, we suggest providing more autonomy support, especially by schools, for the enhancement of autonomous motivation of young people to promote their leisure time physical activity.