The No Child Left Behind Act of 2001 calls for improving test scores of minority students in third through eighth grades, making middle level schools a key venue for closing the racial gap in achievement. This study, by analyzing data on the 15,000 eighth graders who took the 2000 National Assessment of Educational Progress (NAEP) in mathematics, provides evidence that middle level schools can make a difference in Black-White and Latino-White test score gaps. Using multi-level Hierarchical Linear Modeling techniques, this study finds that depending upon the instructional practices that middle school teachers utilize, the achievement gap can be reduced substantially for African American and Latino students. (Contains 3 tables and 4 endnotes.)