Many leading scholars believe that students' emotions affect their learning and performance, and have voiced concerns about the need to investigate these emotions in the context of classrooms and schools. Apart from the emotion of anxiety, very little research has assessed students' achievement emotions toward tests. As high-stakes tests have become a central focus in the education of students, it is essential to better understand what emotions students feel during these assessments. Therefore, this study addressed the academic emotions of anger, anxiety, enjoyment, hope, hopelessness, pride, relief, and shame. Of these, only anxiety, enjoyment, and hope, have been researched in relation to the academic setting. In this study, emotions are investigated in the context of high-stakes mathematics tests and teacher-created mathematics tests in middle school students with mild disabilities. The sample consisted of 51 middle school students with mild disabilities in the Midwestern United States. A modified version of the Test Emotions Questionnaire was used to investigate how students feel about the different assessments. In addition, students' high-stakes mathematics test scores from state-mandated standardized tests and teacher-created mathematics test scores were collected. For the emotions of anxiety, relief, hopelessness, and hope, results showed that students experienced different emotions in regard towards high-stakes mathematics tests when compared to teacher-created mathematics tests. In addition, this study provides evidence that the different emotions students experience related to teacher-created and high-stakes tests are also related to achievement. This study expands the literature on achievement emotions by extending research to middle school students and to students with disabilities, as well as by distinguishing between high-stakes and teacher-created tests. [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.]