This study examined differential and mediating relations between hot and cool self-regulation (Mage = 48.2 months; N = 1,155, 48% girls), first-grade (Mage = 77.5 months) maladjustment (externalizing [EXT] and internalizing [INT] behavior), and first- and second-grade (Mage = 89.5 months) academic competence (AC). Using teacher reported EXT, INT, and AC, partial support for the differential perspective was found in that only hot self-regulation was significantly related to EXT, whereas both hot and cool self-regulation was significantly related to AC. Moreover, hot self-regulation indirectly predicted second-grade AC through first-grade EXT, lending some support for the mediating perspective also. The findings contribute to an understanding of how self-regulation is related to academic and behavioral school adjustment. [ABSTRACT FROM AUTHOR]