Physical activity (PA) infrastructures can provide youth chances to engage in PA. As determinants of organized and unorganized PA (OPA and UPA) may differ, we investigated if proximity to PA infrastructures (proximity) was associated with maintenance of OPA and UPA over 3 years. Youth from New Brunswick, Canada (n = 187; 10-12 years at baseline) reported participation in OPA and UPA every 4 months from 2011 to 2014 as part of the MATCH study. Proximity data were drawn from parent's questionnaires. Proximity scores were divided into tertiles. Kaplan-Meier and Cox proportional hazard models were used to assess associations between proximity and maintenance of OPA and UPA. There were no crude or adjusted differences in average maintenance of participation in OPA [mean number of survey cycle participation (95%CI) was 6.6 (5.7-7.5), 6.3 (5.5-7.1), and 5.8 (5.1-6.6)] or UPA [6.8 (6.2-7.4), 5.9 (5.3-6.5), and 6.6 (5.9-7.3)] across low, moderate, and high tertiles of proximity, respectively. Findings suggest that proximity does not affect maintenance of participation in OPA or UPA during adolescence. Other environmental aspects may have a greater effect. Further research is needed before conclusions can be made.