The primary purpose of this study was to investigate the relationship between length of time in a bilingual program and academic achievement among second grade Mexican American students. One hundred seventy-five students were selected. Their selection was based upon their presence and length of time in a bilingual program. Specifically, the time variable was one, two, and three years spent in a bilingual program. The following instruments were used to obtain data: Self-Concept and Motivation Inventory, Early Elementary Form for Grade 2; Bilingual Syntax Measure, English Version; and Primary Battery of the Iowa Test of Basic Skills. To ascertain the magnitude of the relationship between length of time in a bilingual program, a Pearson product moment correlation coefficient rxy was computed. It was expected that the relationship would be positive. A partial correlation was also computed on the relationship between length of time in a bilingual program and academic achievement, controlling for self-concept, oral English language proficiency, and gender. The level of significance was set at .05. Statistical Findings The analysis of the data revealed four significant statistical correlations: 1. Length of time in a bilingual program does affect a pupil's school achievement. 2. Low self-concept was significantly related to length of time in a bilingual program and academic achievement . 3. For females, there was a significant correlation between length of time in a bilingual program and academic achievement. 4. For the highest level of oral English language proficiency, there was a significant correlation between length of time in a bilingual program and academic achievement. In contrast, this study also revealed no significant relationships: 1. Between length of time in the program and academic achievement for students with a high self-concept. 2. Between length of time in the program and academic achievement for males. 3. Between length of time in the program and academic achievement for levels 3 and 4 on the Bilingual Syntax Measure. [...]