This paper adds to the literature on the relationship between procrastination and academic performance. We measure procrastination as the speed with which students do an online math course on the ALEKS learning platform. This pre-admission course is mandatory for students that are weak in math. Using a large dataset of undergraduate students at a Dutch school of economics, we estimate linear probability models for dropout and graduation rates. Controlling for students' background characteristics, we find that procrastination increases dropout rates and decreases graduation rates. The coefficient estimates indicate that the influence of procrastination on dropout and graduation rates is sizable.