Three meta-analytic studies have shown that bilingual education is an effective method for teaching students who are English language learners. However, there is limited evidence of the effectiveness of bilingual education in preschool. This study used multiple years of data from the Manchester (New Hampshire) Even Start program and relevant comparison groups to conduct two separate tests of the effectiveness of bilingual education in preschool. The results support the effectiveness of bilingual education in preschool, but only at marginally significant levels of statistical inference. A fixed effects model of literacy outcomes comparing a cohort of students who had received bilingual education in preschool but English-only education in kindergarten with a cohort of students who received English-only education in both preschool and kindergarten showed evidence of an achievement gap (favoring the students receiving bilingual education) that emerged at the end of preschool but had closed by the end of kindergarten (10 values ranged from 0.028 to 0.068). Also, an analysis of two years of preschool data from an Even Start program that utilized bilingual education in the first year, but not the second, showed that Even Start students who did not receive bilingual education performed worse on posttest literacy assessments when controlling for pretest scores (p values ranged from 0.056 to 0.060). However, when estimated with a control group consisting of only English language learners, this negative effect was no longer significant. Although the study provides some evidence of the effectiveness of bilingual education in preschool, further research is needed to validate these findings. (Contains 5 tables.)