PurposeBuilding on the premise that top managers' characteristics affect firm outcomes, the study aims to examine whether the impostor feelings of top managers are associated with firm performance.Design/methodology/approachThis study uses survey and regression estimation.FindingsThe results show that there is no strong association between the impostor phenomenon and firm performance, when considering the overall sample. However, in the case of women who experience strong impostor feelings, performance is negatively affected. There is no evidence that being a CEO or workload are mechanisms that explain this result.Practical implicationsImproving the understanding of whether top manager impostor feelings sabotage or improve firm performance can encourage managers to engage in preventive actions to overcome or explore its effects adequately so that positive firm outcomes are fostered.Originality/valueDespite the economic importance of how top managers' judgment affects their decisions, little is known about how the cognitive frames of their top managers affect firm outcomes. In particular, there is no clear understanding of how top managers' feelings of inadequacy, intellectual phoniness and deceitfulness (the impostor phenomenon) affect firm profitability.