This study examines student performance in two foreign language programs, partial immersion (content taught through the exclusive use of a second language) and FLES (Foreign Language in the Elementary School). Are students who study math, science, and social studies through a second language hampered when compared with their non-immersion peers? Does intensive study of a second language interfere with native language usage? Is partial immersion more effective than FLES in producing fluency in the second language? Normal curve equivalent scores of the California Achievement Test (CAT) were used to measure language arts, reading, and math performance. The North Carolina third grade tests for science and social studies were used to measure mastery of state objectives in those subjects. French listening comprehension skills, and in some cases speaking skills, were assessed through the American Association of Teachers of French (AATF) FLES Test. Mental ability was measured using the CTB-McGraw Hill Test of Cognitive Skills. Separate analysis of covariance (ANCOVA) tests were performed for reading, language, math, total battery, science, social studies achievement test response variables. An ANCOVA was also done for French listening skills. A socioeconomic status (SES) Index and IQ scores were used aS covariates in all of these tests. Separate analysis of variance (ANOVA) tests were run on each ANCOVA for the purpose of comparison. Number Cruncher Statistical System software was utilized for all computations. Significant main effects are analyzed. The analysis of scores for both treatment groups revealed there was no difference due to treatment in language, reading, mathematics, science, or total battery. Achievement of FLES and partial immersion groups was Similar. After adjustment for SES and IQ, the immersion group scored significantly less than the FLES group in social studies (p < .05). The immersion group scored Significantly higher than the FLES group in French listening skills (p < .0001). The results of this study provide data to school districts interested in elementary foreign language programs. It contributes to the growing body of research in immersion as an educational alternative. / Ed. D.