The impostor syndrome was first brought to the attention of educators through the work of the feminist psychotherapist, Pauline Clance. Imposterhood is defined as the sense of personal inauthenticity in individuals who evidence achievement. Clance noted this trait was often found in high achieving women, but later work revealed it is found in both male and female samples. In this project we describe the development of a brief impostor scale suited for tertiary student groups. The scale identifies three dimensions, social phoniness, personal phoniness, and inclination to discount success. In a sample of 136 undergraduates we found that impostor scores correlated with pessimism and low need for cognition. Significant relationships were not evident between impostorhood and several measures of general knowledge and vocabulary, although impostors tended to believe they had underperformed on these measures relative to their peers. Significant gender differences in impostor scores were not found.