The Imposter Phenomenon (IP) is an observed anxiety caused by an individual's feelings of fraudulence, fear of being exposed as a fraud, and inability to internalize personal achievement. This study measures the incidence of the IP among librarians at college and research institutions in the United States and Canada and seeks to identify factors that contribute to its frequency. One in eight librarians reported above average IP scores. Younger librarians and those with less longevity experience IP feelings at a higher rate than more experienced counterparts. Also included is a discussion of how to lessen the impact of IP feelings.