Theory and evidence suggest perfectionism is associated with binge eating. Few studies test conditions under which this association is particularly strong. To better understand the perfectionism–binge eating connection, the present study introduced perseveration as a moderator. A sample of 317 undergraduates completed a computerized Stroop task, baseline self-report measures of perfectionism (i.e., doubts about actions) and binge eating, and self-report daily diary measures of binge eating. Perseveration was defined in terms of reaction time difficulties when consecutive trials required a change of response relative to consecutive trials not requiring a change. Results indicated high levels of doubts about actions were especially related to high levels of binge eating for participants high (versus low) in perseveration. Findings suggest perfectionistic, nagging self-doubts, combined with a tendency to get stuck on thoughts or behaviors, may contribute to increased binge eating—a habitual behavior linked with difficulties in self-regulation.