Underrepresented groups on college campuses, first-generation college students (FGCS) face several obstacles which put them at risk of developing Impostor Phenomenon (IP). Research has shown that IP can negatively affect performance, lend to burnout and withdrawal, hinder individuals' abilities to properly assess performance, and inhibit one's ability to reach their full potential which can potentially contribute to an increased risk of attrition. The overarching question guiding this research study is, "What is the relationship between mindset and Impostor Phenomenon in first-generation college students transitioning from high school to a four-year university?" "This quantitative study aimed" to identify whether a relationship exists between mindset and the intensity of Impostor Phenomenon (IP) in first-generation college students (FGCS) transitioning to undergraduate studies. Drawing from Schlossberg's Transition Theory, this quantitative study used descriptive and correlational statistics to analyze survey data gathered from 159 students transitioning from high school to a four-year university. Analyses of the data revealed a high prevalence of frequent to intense impostor experiences in both FGCS and their continuing-generation peers (CGCS). Additionally, the results showed low negative correlations between mindset and the intensity of IP for the overall sample, including FGCS and CGCS, a low positive correlation between fixed mindset and IP, and low negative correlations between growth mindset and IP. Implications of the findings are discussed in Chapter 5. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]