The present research sought to examine when and why transformational and transactional leadership are perceived by followers to be effective. A series of five studies revealed that perceived effectiveness of transformational and transactional leadership is influenced by the fit between leadership style-driven encouraged strategies and followers' preferred strategies. Specifically, we found that transformational leadership primarily encourages promotion-focused strategies and, accordingly, creates a regulatory fit for promotion-focused followers. In contrast, transactional leadership primarily encourages prevention-focused strategies, creating a regulatory fit for prevention-focused followers. As a consequence of this regulatory fit, leadership is perceived as more effective and predictive of enhanced effort. By integrating literature on self-regulation with insights from leadership research, this research contributes to a deeper understanding of the leadership process and of interpersonal influences on self-regulatory experiences. Copyright © 2014 John Wiley & Sons, Ltd.