Flow experience refers to a motivational state of complete concentration on a given task, which can immediately facilitate cognitive performance. Although research has identified feedback as strong antecedent of flow, differences between the effects of positive and negative feedback on flow and the moderating role of personality traits remain largely unexplored. In the present online-based experimental study, we investigated flow as mediator in the effects of normative feedback on performance in a logical reasoning task. Thereby, we also examined moderating effects of locus of control and conscientiousness on indirect effects of positive and negative feedback on task performance via flow. Our sample involved 240 participants, who were randomly assigned to three different feedback conditions (positive, negative, no feedback) after a logical reasoning task. Subsequently, the subjects solved a follow-up task for which they reported the degree of their flow experience. Moderated mediation path modelling showed that positive feedback exerted a positive indirect effect on task performance via flow for highly conscientious individuals. In contrast, negative feedback exerted negative indirect effects on task performance via flow for individuals, who exhibited an internal locus of control or low levels of conscientiousness. Finally, we derived theoretical implications for scholarly understanding of flow experience.