The purpose of this study is to compare students' mathematics achievement growth rate in Texas science, technology, engineering, and mathematics (T-STEM) academies to students' mathematics achievement growth rate in traditional public high schools. Forty-six schools, 23 of which were T-STEM academies and 23 of which were matched non-STEM schools, were included in this study. A hierarchical linear modeling method was conducted. The result of the present study revealed that there was no difference in students' mathematics achievement growth rate in T-STEM academies compared to students' mathematics achievement growth rate in comparison schools. However, in terms of ethnicity, the results indicated that African American and Hispanic students in T-STEM academies outperformed African American and Hispanic students in comparison schools on their mathematics growth rate.