Few educational programs to nurture coach need-supportive behaviors have been delivered by sport governing bodies (Evans et al., 2015). Consequently, the potential for such programs to meaningfully change coaches’ interpersonal behaviors requires further investigation (Cushion et al., 2010). Grounded in self-determination theory, we hypothesized that participation in an educational program would increase youth ice hockey coaches’ self-reported beliefs (e.g., effectiveness; Hypothesis 1) and application (Hypothesis 2) of need-supportive coaching styles. The study comprised 52 intervention coaches and 40 wait-list control group coaches enrolled in a 2-day regular education. Data were collected before the education with follow-up assessments 1½and 3 weeks later. We used multigroup multilevel growth models to analyze the change trajectories of the outcomes. A significant group difference was shown for competence support, for which the intervention group exhibited a greater increase than the control group (Δ = 0.14, SE = 0.05, p =.004). Further, the findings revealed significant increases in the intervention group’s effectiveness (slope mean = 0.11, p =.013) and easy-to-implement beliefs (slope mean = 0.18, p =.026); both conditions significantly increased in autonomy support (intervention group: slope mean = 0.25, p =.006; control group: slope mean = 0.11, p =.006). We found no significant change in the normative beliefs or relatedness support in any condition. The study demonstrates the benefits of a self-determination theory-based coach intervention advocating the collaboration between researchers and sport governing bodies in designing, implementing, and evaluating such endeavors. © 2024 The Author(s)