Dimensions of acculturative stress and their implications for school belonging and achievement were examined among 199 Latino middle-school students. The proposed model hypothesized that school belonging would mediate the association between acculturative stress dimensions and low school achievement. Eighty percent youth of the sample were immigrants, 73% had Mexican origins, 57% were girls, and the mean age of the participants was 13.6 years. A factor analysis yielded two dimensions of acculturative stress: discrimination stress and immigration-related stress. Immigration-related stress was associated with age of immigration, but discrimination stress was not. Findings supported the hypothesis that lack of school belonging may be a mechanism by which "discrimination" stress, but not "immigration-related" stress, decreases school performance among Latino youth. (Contains 1 figure and 3 tables.)