This study investigated the relation between dilatory behaviors and performance in students whom we randomly assigned to either an online or a traditional, lecture introductory psychology class. Both sections had full access to a class Web site. There were no reliable differences between the 2 sections of the class on the measures of procrastination, exam performance, or attitudes toward the class. Yet, procrastination was negatively related with exam scores and with attitudes toward the class for the online students, but not for the lecture students. This difference may partially explain why online courses designed to increase the educational efficacy of a course often show no difference in performance when compared to lecture classes.