An attitudinal resistance among teachers regarding the inclusion of children with disabilities is well documented in the literature. Studies collectively highlight two specific areas that contribute to this resistance. First, a lack of teacher knowledge or preparedness for meeting the diverse needs of children with disabilities stimulates resistance to change. Additional opposition stems from the pressure educators associate with the expectation of children with disabilities to perform at a proficient or mastery level on assessments of grade level objectives. Therefore, due to the expectation for all students to proficiently participate in the rigorous curriculum of the twenty-first century, this study examined professional development needs of elementary school teachers related to differentiating instruction for successful inclusion of special education students in general education classrooms (Bosch & Edgar, 2001; Ellett & Teddlie, 2003; Hastings & Oakford, 2003; Lesyer & Tappendorf, 2001). Regarding teacher knowledge and preparedness, researchers have investigated ways to meet the demanding needs or challenges of teaching children with disabilities in the general education environment. Specifically examined was the role that both teacher education programs and school leaders play in preparing teachers for responding to the needs of children with disabilities in inclusion programs (Browder et al., 2007; Forsten, Grant, & Hollas, 2002; Hedeen & Ayres, 2002; McLeskey & Waldron, 2002; Miller, 2006). Numerous studies revealed the role of teacher education programs and professional development for teachers in regard to teaching children with disabilities in an inclusion setting (Agran, Alper, & Wehmeyer, 2002; Browder, 2003; Cawley, Hayden, Cade, & Baker-Kroczynski, 2002; Geiger, 2002). Limited to soliciting data from the elementary arena (kindergarten through grade 5) this study included as participants the following educators: teachers with National Board Certification, school administrators, and two district-level subgroups from the third largest school district in Mississippi. Focus group methodology was utilized in this study because of its effectiveness to achieve an applicable understanding of professional development needs for inclusion (Eells, 2003; Fern, 2001; Goldenkoff, 2004; Krueger & Casey, 2000; Larson, Grudens-Schuck, & Allen, 2004; Larson & Hegland, 2003). Findings included the need for school leaders to conduct further research in the cultural change process for schools as well as the need for institutes of higher learning to examine pre-service collaboration between general and special education degree programs. [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.]