Not enough research has been conducted to determine what can support and encourage successful African-American students in mathematics. Many environmental and personal factors have been identified that may impact the success of African-American students in mathematics but studying and relating these factors at a qualitative level would benefit from additional research (DeCuir & Dixson, 2004). The purpose of this research was to investigate a group of African-American students who are successful in mathematics, where success is defined as taking a higher-level mathematics course compared to others in the same grade and maintaining an A or B in that course. All participants in this study are students who identify as African-American and are currently enrolled in a magnet high school for academically talented students. An instrumental case study research design was used for the study. A survey that consisted of Likert scales was used to collect personal data, in addition to data that could be analyzed to determine the impact on the self-efficacy of the students in mathematics as it relates to environmental and personal factors of all the African-American students at the school. Nine students who participated in answering the survey questions were purposefully selected to participate in in-depth semi-structured interviews. The in-depth semi-structured interviews, which were audio recorded and transcribed, were used to collect responses from the participants. Qualitative analysis of the data in the form of creating themes from the interviews were used to delve deeply into the students' perceptions of their self-efficacy and personal beliefs as it relates to mathematics. In general, the results from this study provided confirmation of the findings from previous research. The most important findings discovered from this study were that the parents and teachers of African-American students who are classified as successful in mathematics are supportive of them and there is some connection between self-efficacy and success for African-American students in math. This research study was significant because it gives an account of why African-American students were successful in mathematics in their own words. [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.]