This study investigates whether and how vertical leader transformational and transactional styles impact team members' perceptions of shared leadership. It also investigates the mediating role of a leader's attitude to sport on these relationships. Using a matched sample of 154 team leaders and 354 team members from agile teams in two MNCs located in Ireland and China, we found that both vertical transformational and transactional leadership were linked to team members' shared leadership behavior; however, the impact of transformational leadership was significantly greater. We also found that a vertical team leader's attitude to sports, and specifically the pleasure and participation attitude, positively mediated the relationship between transformational and transactional leadership and shared leadership behavior. This contrasted with the power and performance sports attitude, which mediated both transformational and transactional leadership styles, but for which the impact of transactional leadership on shared leadership became negative. We extend research on the antecedents of shared leadership and the important role that both a vertical leader's style and attitudes play within an agile software team. We discuss implications for theory and practice.