For the past 30 years, educators have been challenged with mainstreaming students with disabilities into regular classrooms. Research has shown that teachers often lack the knowledge and training to implement inclusion programs effectively. Guided by Bandura's social cognitive theory, with a particular focus on self-efficacy, this mixed method, non-experimental, sequential explanatory design investigated teachers' attitudes toward children with disabilities who participated in their noncore classes of art, music, physical education, library, and computer studies. From a sample of 525 noncore teachers, 91 completed a quantitative 2-part survey. Data were analyzed by descriptive statistics, which found that on a 1 to 4 Likert scale of teachers' positive attitudes towards inclusion, the mean was less than 3. Qualitative data collection involved individual interviews with 10 teachers. A thematic analysis was employed to analyze these qualitative data, which revealed that teacher attitude was negatively impacted by lack of training, lack of support, the degree and type of the student disability, and limited involvement from the administrators. These findings suggest that revamping the curriculum in teacher training and certification programs would better equip new teachers to address the needs of the special education students in their classrooms. The modified curriculum would emphasize teaching to the strength of the students and understanding how the different types of disabilities impact students' ability to learn. The modified curriculum would address developmental levels as well, thus empowering new teachers to handle multiple educational needs within their classroom and guiding them to better assessment and student achievement. [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.]