<p>The relationship between perfectionism and procrastination has long been concerned, but the underlying mechanism and boundary condition have been understudied. This study examines the influence of leader-follower (in)congruence in perfectionism on follower decisional procrastination with follower introjected regulation (work motivation) serving as a mediator. The data were collected from a sample of 439 individuals in mainland China at three time points. Polynomial regression and response surface methodology were used to analyze the relationship between leader-follower perfectionism (in)congruence and follower introjected regulation. Besides, block variable methodology was employed to test the mediating effect of introjected regulation. The results indicated that follower introjected regulation is highest when leader and follower perfectionism are congruent, and the congruence effect is stronger when leader and follower perfectionism are high rather than low. Finally, leader-follower perfectionism congruence decreases follower decisional procrastination via follower introjected regulation. These findings shed light on the psychological mechanism linking perfectionism to procrastination and provide effective strategies about leader-follower fit.</p>