This study examines the impact of the inclusive environment on student performance. As schools work to comply with the Least Restrictive Environment requirement of the Individuals with Disabilities Education Act, including students into the general education environment has become the norm as opposed to the exception. The improvement in performance for students with disabilities in the inclusive environment has been well documented. However, there is a significant gap in the research regarding the performance of students without disabilities in the inclusive environment. The intent of this study was to focus on that group of students without disabilities and their performance in the inclusive environment compared to their performance in a segregated environment given an otherwise identical curriculum and course mapping. This quantitative study utilizes a quasi-experimental design. Student performance was measured using the statewide, standardized assessment. This study found that there was no significant difference between the performance of students without disabilities in the inclusive versus segregated environments in the content areas of social studies, science, and reading. This study also revealed that students in the segregated environment performed significantly better than students in the inclusive environment in the area of 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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]