This study investigated how and when spiritual leadership behavior enhances employee career growth potential. Building on self-determination theory, we cast autonomous motivation (I will do) as a novel explanatory mechanism to explain why spiritual leadership behavior enhances employee career growth potential. In addition, we propose that the relation between autonomous motivation and career growth potential depends on political skill (I can do). In Study 1, a new spiritual leadership behavior (SLB) scale, was developed and preliminarily validated. In Study 2, we tested the proposed theoretical model with data gathered across three phases over 2 months from 277 employees and their 71 supervisors. The results indicated that spiritual leadership behavior stimulated employees’ autonomous motivation, which in turn enhanced their career growth potential. Furthermore, for employees high in political skill, spiritual leadership behavior was associated with greater career growth potential rated by supervisors as increased autonomous motivation; this indirect relation did not exist for employees with low political skill.