<p>Scholarly interest in calling has increased dramatically over the last decade. Drawing on the self-concept theory of career development, this study proposes that transformational leadership contributes to living a calling, which in turn improves job satisfaction and workaholism, indicating both the bright and dark sides of living a calling. With a sample of 514 firefighters nested in 56 work units, the idea was tested with multilevel analyses. The results showed that leaders’ transformational leadership was positively related to living a calling of followers and leaders themselves; and living a calling was positively related to job satisfaction and the workaholism of followers and leaders, indicating the mixed effects; that means that living out a calling may lead to the benefits and costs to leaders and employees simultaneously. This study extends the understanding of antecedents and outcomes, and the dark side of living a calling.</p>