To maximize the effectiveness of coach development, educational programs should target coaches’ interpersonal behaviors, be informed by behavior-change techniques, and incorporate comprehensive evaluation procedures. Thus, informed by the full-range leadership model (see Bass and Riggio in 2006) and the Behaviour Change Wheel (see Michie et al. in 2011), Turnnidge and Côté in 2017 developed the Transformational Coaching Workshop (TCW). The purpose of this study was to evaluate the TCW’s effectiveness through observation before and after coaches’ workshop participation. Participants included 8 male head coaches of youth soccer teams. Systematic observation and coding using the Coach Leadership Assessment System were employed pre- and postworkshop to examine coaches’ leadership behaviors. Coaches made improvements in the types of leadership behaviors used and how they were conveyed. This study demonstrates that systematic observation can be implemented to explore real-world changes in behaviors. Future research should examine the impact of the TCW on athlete outcomes.