This study examined the mediating effect of cognitive trust felt by followers in the relationship between leader’s self-promotion and leadership effectiveness, and the moderated mediating effect of leaders' humility as leader characteristics. A survey of 253 soldiers below the rank of Army Major found that the leader's self-promotion had a significant relationship with leadership effectiveness, and that the leader's humility moderated the leader's self-promotion and leadership effectiveness mediated by cognitive trust. Results and theoretical and practical implications of this study were discussed.