Research on college access and enrollment indicates that a college education is one of the most effective avenues to increase social mobility. Each year, low-income students of color face a number of barriers to college access and success at every stage of their educational trajectory (Gandara, 2000; Gandara, 2002; Gandara & Contreras, 2009; McClafferty & McDonough, 2000; McDonough, 1997; Obama, 2014). Students from low-income backgrounds are not only less likely to complete high school, but also much less likely to enroll in postsecondary education among those who graduate from high school (Chapman, Laird, & Kewal Remani, 2011). Much of this gap persists because low-income students often lack the guidance and support they need to navigate college preparation--from test taking, to the application process, to applying for financial aid (De La Rosa, 2006; McDonough, 1997). Perhaps even more disheartening is the number of qualified high-school students who end up choosing a college that is not a good fit for them or do not go to college at all. A popular explanation for this potential cause of class-based postsecondary stratification is the college application and enrollment behaviors of low-income students. A growing body of research suggests that a significant pool of first-generation, low-income students undermatch in their college choice process that is when students fail to enroll at a 4-year university despite being academically qualified to do so. As a result, many college-qualified low-income students disproportionately attend less selective institutions, fail to enroll in college altogether or are mostly concentrated in community colleges. Therefore, improving the rate at which low-income students choose universities that "match" their academic qualifications requires an understanding of the factors that contribute to this undermatching in the first place. As such, this study is the first attempt to study the pervasiveness of undermatching among first-generation, low-income Latina/o students and suggest why such phenomenon deserves greater attention from scholars and policymakers alike. This study was guided by the following overarching question: What are the factors that contribute to the college undermatching of first-generation, low-income high school Latina/o students? In order to answer this central question, the following purposeful research questions were also addressed in the study: What role does the high school environment (organizational habitus) play in the college undermatching of Latina/o students? What role does school-based institutional agents (teachers, counselors, mentors, etc.) play in the college undermatching of Latina/o students? To examine the factors that contributed to the college undermatch of first-generation, low-income Latina/o students, this study used a qualitative research design generated from one-on-one, in-depth semi-structured interviews. Thus, the student voices shaped this body of work. Overall, findings in this study suggest that unlike some traditional college students, Latina/os face an array of economic, social, cultural, family, and institutional barriers that affect their likelihood of enrolling in a 4-year university that matches their academic qualifications. All students in this study with the exception of two ended up enrolling in a local community college. Specifically, it was found that the following six major factors contributed to a student's college undermatch: (a) financial constraints, (b) family constraints (c) institutional barriers, (d) lack of self-efficacy, (e) sense of college readiness, and (f) lack of college knowledge. In addition, a major finding was that the high school environment did not play a significant role in the college undermatching of students. In fact, the decision on where to go to college was mostly done on their own without the influence of their high school. Results revealed that although students agreed that the message was to go to college and they perceived their high school as having an intermediate to strong college-going culture, it did not correlate with students enrolling in a 4-year university. Similarly, it was found that school-based institutional agents did not play a significant role in the students' college undermatching. However, it was found that students relied heavily on the hands-on support they received from college prep programs like the Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) to navigate the college and financial aid application process. Without this support, student perhaps would have not been able to follow through with the college enrollments steps needed to enroll in a community college. Grounded in the belief that the future of Latina/o students and their families is deeply connected to the future of our country, this study is both timely and relevant. This study offers new insights regarding the complexities faced by Latina/o students as they navigate the U.S. educational pipeline. This study also contributes to the growing body of research focused on the latest college choice literature and highlights the complexities of the college choice process. Finally, this study provides policy, programmatic, and research recommendations to strengthen the educational pipeline of first-generation, low-income Latina/o students. [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.]