In the U.S., college transition grows increasingly difficult, with students experiencing rising levels of stress and anxiety. Such challenges may arise as students face normative but novice stressors while working towards professional goals. Students' ability to engage in successful self-regulation may be especially important in response to these challenges. The goals of the present study were to assess a) the mediating role of self-regulatory behaviors on the relationship between trait emotion regulation and negative affect (NA) on the day of a first major college exam; and b) the mediating role of exam-day NA on the relationship between self-regulatory behaviors and exam performance. Results show that trait-level challenges in emotion regulation are associated with increased procrastination behaviors in the days before the exam, which in turn is associated with higher NA on exam day. Implications are discussed for well-being and success of students, particularly for students who struggle with self-regulation.