For the past three decades, much attention has been focused on developing diversity programs designed to improve the academic success of underrepresented minorities, primarily in mathematics, science, and engineering. However, ethnic minorities remain underrepresented in science majors and careers. Over the last 10 years, the Biology Scholars Program (BSP), a diversity program at the University of California (UC), Berkeley, has worked to increase the participation and success of students majoring in the biological sciences. A quantitative comparison of students in and out of the program indicates that students in BSP graduate with a degree in biology at significantly higher rates than students not in BSP regardless of race/ethnicity. Furthermore, students who are in BSP have statistically lower high school grade point averages (GPAs) and Scholastic Achievement Test (SAT) scores than students not in BSP. African-American and Hispanic students who join BSP graduate with significantly higher UC Berkeley biology GPAs than non-BSP African-American and Hispanic students, respectively. Majority (Asian and White) students in BSP graduate with statistically similar UC GPAs despite having lower SAT scores than non-BSP majority students. Although BSP students are more successful in completing a biology degree than non-program members, the results raise a series of questions about why the program works and for whom.