The purpose of this study was to ascertain the effectiveness of Two-Way Bilingual Immersion programs in closing the achievement gap of minority students. More specifically, this study was concerned with the outcomes of any differences of certain student demographics primarily, the variables ethnicity, gender and socioeconomic status of students' academic achievement as measured on the Texas Assessment of Knowledge and Skills (TAKS) in Two-Way Bilingual Immersion programs. Secondly, this study examined the differences in academic achievement for students enrolled in Two-Way Bilingual Immersion programs; specifically, the 90/10 model as measured on the Texas Assessment of Knowledge and Skills (TAKS). Thirdly, this study analyzed the differences in academic achievement for students enrolled in Two-Way Bilingual Immersion programs compared to students enrolled in Regular Monolingual Education programs.

A causal comparative (Ex Post Facto) design was employed in this investigation. The sample population of this study consisted of the entire population of 846 elementary students enrolled at 9 elementary campuses with Two-Way Bilingual Immersion programs beginning in the 2002–2003 school year. The researcher investigated the academic data of this cohort in this large urban school district located in the southeast region of Texas as the students matriculated from kindergarten through fifth grade.

Using the One-Way Analysis of Variance to analyze all the data formulated for this study, the researcher examined the independent effects of one independent variable on a dependent variable of students enrolled in Two-Way Bilingual Immersion programs. All hypotheses generated for this study were tested at the .05 level of significance or better.

Based on the findings derived from this empirical study, the following conclusions were determined: (1) By fifth grade, students enrolled in Two-Way Bilingual Immersion programs outperformed their peers enrolled in Regular Monolingual Education programs on the reading section of TAKS. (2) By fifth grade, NES students enrolled in Two-Way Bilingual Immersion programs outperformed their peers enrolled in Regular Monolingual Education programs on the TAKS reading section. (3) By fifth grade, NSS students enrolled in Two-Way Bilingual Immersion programs outperformed Waived NSS students enrolled in Regular Monolingual Education programs on the TAKS math and reading sections.