Two studies investigated the role of impulsivity in procrastinators' problems. In the first study, 147 freshmen completed questionnaires measuring the Big Five personality factors, a broad impulsivity scale, and Lay's general procrastination scale, and their perceptions concerning a compulsory course. The data revealed that procrastination was closely related to a lack of perseverance, that is, the inability to complete projects. This relation explained a large part of the well documented relation between conscientiousness and procrastination. In the second study, a subsample of these students was followed up during 11 weeks before their exams. They had to provide their study intentions and behaviour, the reasons why they failed to enact their intentions, and the perceived impact of studying on their final grade. The data revealed that all students tend to postpone the bulk of their study activities to the last week before an exam, and that this trend could nicely be described by a hyperbolic curve. The results also revealed that procrastinators postponed more of their intentions, mainly because of fun alternatives, but did not intend to study less or later. On the contrary, they even seemed to compensate for their vulnerability by formulating more intentions earlier. Procrastinators emerged as highly motivated students who lack the ability to ward off temptations and distractions during their studying activities. Copyright © 2002 John Wiley & Sons, Ltd.