A growing body of research suggests that academic procrastination is a dynamic behavior that follows a curvilinear trajectory over time. In this research, we examined whether there are inter-individual differences in this trajectory, the extent to which these differences can be predicted by other variables, and the relationship between temporal changes in procrastination and academic outcomes. We collected multi-wave data from 303 students regarding their actual procrastination behavior and test performance during an academic semester, as well as single measurements of their self-reported levels of trait procrastination, conscientiousness, and neuroticism. Using latent growth curve modeling, we found that high and low procrastinators followed the same trajectory over time, that the self-report measures did not predict temporal changes in procrastination and test performance, and that procrastination behavior was negatively related to test performance throughout the semester. The implications of these findings for trait-based theories of procrastination, and the measurement of procrastination in general, are discussed.