In this dissertation, the effects of bilingual immersion curriculum versus monolingual curriculum on achievement of students in a select elementary school were examined. The researcher explored mathematical and reading achievement as measured by formative kindergarten through third grade assessments in a southeastern elementary school. Hypotheses were tested by conducting factorial ANOVAs for mathematical automaticity, reading fluency, and reading readiness. The independent variables were setting and grade level. The dependent variable was achievement. National percentile norms indicating overall achievement scores of participants were utilized to see if there was any interaction amongst the factors as well as conducting a mean comparison. Analyses yielded setting as the only factor that had statistically significant differences between general education students and those in the bilingual immersion program. The mean scores in were higher for the latter in all three areas of mathematical automaticity, reading fluency, and reading readiness. Effect sizes also suggested a moderate effect of setting on all three factors. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]