The increasing number of culturally and linguistically diverse students entering school in the United States has created an urgent call to prepare teachers to meet the demands of these students. A teacher education program designed to adequately prepare teachers to instruct culturally and linguistically diverse students is the needed response. This program should help teachers to see that diverse student learners can achieve academic excellence. To add validity to this belief, the program should be empirically validated for use in local school districts. The purpose of this quasi-experimental study, which was based on Ladson-Billings's theoretical framework, was to determine the impact of culturally responsive pedagogy on the mathematics achievement of African American middle school students' achievement. A repeated-measures ANOVA that included Grade 8 students' mathematics developmental scale scores over time (3-year cohort) compared scores between the treatment group (6 teachers who participated in professional development in culturally responsive pedagogy) and the control group (6 teachers who did not participate) at a school in the southeastern U.S. The results of the repeated-measures ANOVA offered evidence for the need to implement a culturally responsive pedagogy to promote the achievement of all students. Recommendations included implementing a culturally responsive pedagogy in order to improve students' developmental scale scores in mathematics and overall achievement. This study informs social change by supporting the power of culturally responsive pedagogy and contributes to the academic achievement of diverse learners in mathematics. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]