This study examined the relative impact of intrinsic and extrinsic motivation and personality variables on procrastination behavior of college students. A total of 96 undergraduates completed the Procrastination Assessment Scale-Students, the Multidimensional-Multiattributional Causality Scale, the Brief Fear of Negative Evaluation Scale, the Work Preference Inventory, Burns' Perfectionism Scale, and the Locus of Control Scale. Multiple regression analyses of the results found that lack of extrinsic motivation, perfectionism, and an external attributional style all predicted the tendency to procrastinate. On the other hand, low procrastinators were motivated by both external and internal factors more than high procrastinators, while high procrastinators put off tasks due to aversion. Students with low intrinsic motivation made attributions to context and luck, particularly when they succeeded, while students with higher levels of intrinsic motivation made attributions to ability and effort for success, and effort for failure. Lack of extrinsic motivation contributed to procrastination for all students. (Contains 40 references.) (MDM)