The current study examined how the Maladaptive Evaluative Concerns (MEC) versus Positive Achievement Striving (PAS) dimensions of perfectionism relate to anxiety, goal-setting, and cognitive appraisal in third-grade to sixth-grade students who completed an object-naming task under three goal-demand conditions: self-set goals, and low and high experimenter goals. The results indicated that children high on a measure of socially prescribed perfectionism (SPP; a measure of MEC) experienced more anxiety across all conditions than children low in SPP. Children scoring high on SPP also rated performing well on the task as more important and were more likely to say they should have performed better than their low SPP counterparts, despite no significant differences in performance or standard-setting. The PAS component of perfectionism was unrelated to children’s responses. These results are consistent with Beck’s cognitive theory and support the utility of the maladaptive evaluative concerns dimension of perfectionism in predicting children’s cognitive and affective responses to new tasks.