Drawing on theories of emotional contagion and goal setting, we propose two mechanisms as to how employees' perceptions of entrepreneurial passion influence their commitment to entrepreneurial ventures. Testing these mechanisms with data from a survey of 124 employees, we find that employees' perceptions of their supervisors' passion for inventing, founding, and developing differentially impact commitment. While perceptions of entrepreneurs' passion for inventing and developing enhance commitment, passion for founding reduces it. Employees' experiences of positive affect at work and their goal clarity mediate these effects. Our results have implications for the literature on entrepreneurial passion and leadership in entrepreneurial firms.