In this article, the authors report on research that aims to understand diversity in STEM and the principles of good practice in undergraduate science education that will improve rates of degree attainment and advancement into graduate studies in related fields among underrepresented racial minorities (URMs). Although students' precollege characteristics are important determinants of degree completion, Seymour (1992) suggests that many talented students do not pursue scientific research careers. To better understand what factors influence URM students' success, the UCLA Higher Education Research Institute (HERI) selected a targeted sample of college students who are majoring in biomedical and behavioral sciences and other STEM fields. We use data obtained through the Cooperative Institutional Research Program's (CIRP) 2004 Freshman Survey (TFS) and the 2005 Your First College Year (YFCY) survey, which were administered during fall orientation and at the end of the freshman year. Using this national data set with the 2004 cohort as a baseline, the authors have sought to identify the conditions and practices within colleges and universities that increase retention in STEM and prepare students for graduate study and STEM-related careers. The authors summarize findings and offer implications from the first phase of this national longitudinal study.