The study compares two groups of students who graduated from high school in the Milwaukee Public Schools (MPS) during 1997-2001. Students who had participated in MPS Montessori programs from preschool through 5th grade were matched to a comparison group on the basis of gender, SES, race/ethnicity, and high school attended. Data from the ACT and WKCE, as well as overall and subject-specific high school grade point averages, were used in exploratory and confirmatory factor analyses. Once a model was established, the factors were regressed on the students' demographic characteristics and type of elementary education in a structural equation modeling framework. The Montessori group had significantly higher scores on tests associated with the math/science factor. There were no significant group differences for the factors associated with English/social studies and grade point average. (Contains 5 tables and 1 figure.)