The Louis D. Brandeis High School Bilingual Program served 900 New York City Hispanic students with limited proficiency in English. In addition to developing English and Spanish language skills the program provided content area instruction in Spanish in social studies, mathematics, and science. Staff development, mainstreaming, parental involvement activities, and supportive services formed additional program components. Criterion referenced tests were used to evaluate the effects of the program on student performance. Evaluative findings indicated that (1) students mastered a majority of objectives in English as a Second Language instruction, (2) all students made gains in reading Spanish, although only at the ninth grade level were gains significant, (3) only ninth graders in the fall term met the mathematics criterion, (4) almost half the students reached the criterion of achievement in science, (5) all twelfth graders and half of the students in other grades reached the criterion level in social studies, (6) all students exceeded the criterion in Spanish language arts, and (7) most students appeared to be making progress in oral English proficiency. Bilingual program students had average attendance rates of 88-92%. Recommendations for future program implementation are included. (MK)