This study traced the development of gender differences in learning opportunities, achievement, and choice in mathematics among White, African American, and Latino students using data from a nationally representative sample of eighth-grade students who were resurveyed in the 10th grade. It found that in this age group, female students do not lag behind male students in test scores and grades and that White female students are exposed to more learning opportunities in mathematics than are male students. However, all female students tend to have less interest in mathematics and less confidence in their mathematics abilities. Gender differences are the largest among Latinos and the smallest among African Americans. Furthermore, the major barriers to mathematics achievement for White female students are attitudes and career choices and for minority students of both sexes, they are limited learning opportunities and low levels of achievement.