Perfectionism, the tendency to set high standards and to evaluate oneself in an overly critical fashion, has been hypothesized to be associated with a host of psychological problems, yet little research has been done on it. This study examined the role of perfectionism in cognitive, affective, and behavioral responses to an evaluated writing task. Compared to nonperfectionists, perfectionists assigned the task greater importance at the outset, reported higher levels of negative affect when the evaluative component of the task was emphasized, and, following the task, were more likely to report that they should have done better. Moreover, their work was judged to be lower in quality. Further research on perfectionism and task performance is warranted. © 1990 Plenum Publishing Corporation.