This study examines the disparities in, changes in, and longitudinal interrelationships among mathematics achievement and motivational factors for Hispanics and their White, Black, and Asian peers throughout high school. Analyzing the nationally representative High School Longitudinal Study of 2009, regression results indicate that Hispanics trail other racial/ethnic groups in math cognitive and psychosocial factors, except that they outperform their Black counterparts in math standardized assessments. Cross-lagged path analyses further reveal that while math intellectual competencies and expectancy-value beliefs are generally reciprocal over time for all racial/ethnic groups, the estimated effect of initial math expectancy on subsequent math test scores for Hispanics is 2.4 to 2.6 times larger than for non-Hispanics. This finding highlights the distinctive developmental patterns of math achievement and motivational factors for young Hispanic students, which have important implications for research and practice on increasing participation of Hispanics in science, technology, engineering, and mathematics (STEM) education and careers.