Findings suggested that the relationship between engagement and achievement might be moderated by race and ethnicity. Racial/ethnic difference in Grade Point Average (GPA) showed Black students reporting lower grade point averages than White students and Asian students, and that socioeconomic status was strongly related to GPA. Results pertaining to engagement and other indicators of students' classroom experience, however, defied common assumptions of the relationship between engagement and achievement; Black students reported higher levels of engagement, intrinsic motivation, and affect than other ethnic groups, yet lower levels of achievement. White students reported lower engagement than any other ethnic groups, yet higher achievement except for Asian students. Asian students reported higher achievement than other ethnic groups, but not higher engagement. Student engagement is a significant predictor of GPA for White students after controlling for socioeconomic and other background characteristics, while engagement and GPA appear to be inversely related for Black students. Ethnic and racial differences in engagement and achievement were not as consistent for Asians and Latinos. Latinos, for example, were similar to White students on most of the experiential outcomes of interest, and neither Latino nor Asian ethnicity significantly moderated the positive association between engagement and achievement. While socioeconomic status had virtually no effect on engagement or students' quality of experience in classrooms, community socioeconomic status appeared to be negatively related to student engagement as well as self esteem, intensity, intrinsic motivation, and affect. Data were collected from the Sloan Study of Youth and Social Development, a national longitudinal study investigating experiences of students as they are socialized into adulthood. The sample of students (N=586) was drawn from 13 high schools diverse in ethnic and socioeconomic populations. Tables, figure, references