The immediate benefits of research experiences for undergraduates have been documented. However, little has appeared about the long-term impacts of these experiences on participants' career trajectories and their level of career satisfaction. In addition, many studies of undergraduate research lack a comparison group. This article reports a comparison of results from a survey of participants in the University of Arizona (UA) Undergraduate Biology Research Program (UBRP) with those of a comparable group drawn from the UA College of Medicine who did not participate in UBRP. Findings indicate that exposure to undergraduate research clarifies career paths and demonstrates to many students that they have an aptitude for scientific research that has a strong effect on their professional development. Participation in research for many who pursue medical careers tends to be "instrumental" in that it is seen as a means of becoming a more competitive medical school applicant. Both the UBRP group and the College of Medicine group indicated that mentors were key to determining and achieving their professional success. Response rates suggest that an organized undergraduate research program fosters a feeling of community and engenders an enduring sense of loyalty within a large institution.