Evaluation of a structured immersion program, operating since 1968 in Uvalde, Texas as part of the United States Department of Education's Project Follow Through, suggests that the structured immersion approach has had a consistent positive effect on the academic achievement of the language minority students involved. Approximately 130 Spanish speaking Hispanic first grade students (83% classified as low income) enter the program each year, with approximately 100 students completing the 3 full years of the Follow Through program, which involves direct instruction by bilingual teachers and aides using a controlled vocabulary to teach needed skills and problem solving strategies to allow disadvantaged students to function at the same level as their peers. Evaluation of Comprehensive Test of Basic Skills, 1970 Metropolitan Achievement Tests, and Wide Range Achievement Test scores of students completing the program for 11 years indicate that achievement levels have been at or near grade level in mathematics and written language for over a decade. Performance on tests of oral reading are above grade level and scores in reading comprehension/vocabulary are at the 28th to 31st percentile, appreciably above typical levels for low income Hispanics. Follow-up studies conducted 2 and 3 years after students completed the program indicate significant, enduring effects in achievement. (NEC)