Different models of school sport delivery, such as intramurals (IM), may attract students who are less skilled or less interested in traditional varsity sports (VS). The purpose of this study was to examine whether school sport delivery models (IM or VS) differentially influence middle school students' motivations to participate in school sports. Using the theory of planned behaviour (TPB) as a conceptual framework, participants in school sponsored sport programs (n = 2,021) from four middle schools (2 IM; 2 VS) completed a school sport participation questionnaire at the beginning and end of a school year. Results suggest that intentions to participate in sport either increase or are maintained through participation in school sports, and the intentions of non-participants decrease over time. A singular model of school sport that only includes highly competitive varsity sports may limit opportunities for children to play sport and diminish their intentions for enduring sport participation.