African American students are not achieving at the levels of their white and Asian counterparts on all measures of achievement including standardized assessments, particularly in mathematics. The existence of a mathematics achievement gap signifies a breakdown in the teaching and learning of mathematics for African American students. This achievement gap is pervasive in urban schools. Researchers have found that teachers' beliefs have a profound influence on the instructional practices enacted in the classroom. By conducting an interpretive case study, this study attempted to understand urban middle school mathematics teachers' beliefs about their African American students and determine the influence of those beliefs on their instructional practice. The results of this study revealed the existence of three beliefs that the participants held about their African American students. The three beliefs are (a) African American students have the natural ability to learn mathematics, (b) African American students' learning is enhanced when they engage in out-of-school learning experiences, and (c) African American students need classroom instruction that emphasizes conceptual understanding. These beliefs resulted in the participants delivering classroom instruction that was driven by high expectations, rooted in differentiated instruction, and promoted rich classroom discourse. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]