In search of antecedents of the imposter phenomenon, this paper examines whether perceptions of an ethical climate change how an individual’s concern over mistakes and personal standards relate to the impostor phenomenon. Concern over mistakes, when taken to extremes, can result in dysfunctional interactions with others. We propose that an individual’s perception of the ethical climate is likely to influence how concern over mistakes and personal standards influence the impostor phenomenon. The results, based on over 600 students, reveal that both ethical climate and the two facets of perfectionism are linked to the imposter phenomenon. Notably, when there is a strong ethical climate, there becomes an increased positive relationship between concern over mistakes and the imposter phenomenon. Similarly, in the presence of a strong ethical climate, there is an increased positive relationship between personal standards and the imposter phenomenon. Practical implications suggest that the ethical climate of colleges of business may influence students’ thoughts of being an imposter and contribute to future maladaptive beliefs.