Understanding racial, ethnic, and immigrant variation in educational achievement and attainment is more important than ever as the U.S. population becomes increasingly diverse. The Census Bureau estimates that in 2000, 34% of all youth aged 15-19 were from minority groups; it estimates that by 2025, this will increase to 46% (U.S. Census Bureau 2000). In addition, approximately one in five school-age children reside in an immigrant family (Zhou 1997, Suarez-Orozco & Suarez-Orozco 2001). We provide an overview of recent empirical research on racial, ethnic, and immigrant differences in educational achievement and attainment, and we examine some current theories that attempt to explain these differences. We explore group differences in grades, test scores, course taking, and tracking, especially throughout secondary schooling, and then discuss variation in high school completion, transitions to college, and college completion. We also summarize key theoretical explanations used to explain persistent differences net of variation in socioeconomic status, which focus on family and cultural beliefs that stem from minority group and class experiences. Overall, there are many signs of optimism. Racial and ethnic gaps in educational achievement and attainment have narrowed over the past three decades by every measure available to social scientists. Educational aspirations are universally high for all racial and ethnic groups as most adolescents expect to go to college. However, substantial gaps remain, especially between less advantaged groups such as African Americans, Hispanics, and Native Americans and more advantaged groups such as whites and Asian Americans. The racial and ethnic hierarchy in educational achievement is apparent across varying measures of the academic experience.