The purpose of this study was to determine if significant changes have occurred in the instructional placement and state assessment participation rates of special education students in the state of Texas since the implementation of the No Child Left Behind Act of 2001. Data analyzed included the instructional placement data for the years of 2002 and 2006, the percentages of special education students who participated in the Texas Assessment of Academic Skills (TAAS) or Texas Assessment of Knowledge and Skills (TAKS) during the same 2 years, and the relationship between the percentages of special education students in sampled districts who participated in TAKS and the state accountability ranking earned by those school districts. Results revealed a significant difference in instructional placements for both less restrictive placements and more restrictive placements for students with disabilities. No significant difference was found in the state assessment rates of special education students who took alternative assessments between the spring of 2002 and the spring of 2006. No correlation was found between the state accountability ratings assigned to a district and the percentage of students with disabilities served by the district. The findings regarding instructional placement suggest that the No Child Left Behind Act of 2001 had a positive influence in moving students with disabilities to less restrictive placements, however no evidence was found to suggest a corresponding change regarding participation of special education students in regular grade level state assessments. [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.]