The purpose of this study is to examine how 659 Hispanic students in dual language programs in segregated or predominantly Hispanic/low socio-economic status (SES) schools are performing on standardized tests compared to school and statewide comparison groups. Test results are presented from two separate studies of English language learner and native English-speaking Hispanic students in four schools. Data are consistent in showing that Hispanic students participating in dual language programs in predominantly Hispanic/low SES schools achieve at similar or higher levels compared to their mainstream peers in tests of English. In addition, students achieve above grade level in assessments in Spanish. This study affirms the versatility of the dual language program for this increasingly common educational context. (Contains 4 tables, 2 figures and 5 notes.)