Research has shown teachers' attitudes toward students with disabilities directly affect the students' performance in the general education classroom; however, more research is needed to determine what variables influence high school teacher and support staff attitudes. The purpose of this study was to determine the attitudes of high school general education teachers, special education teachers, and support staff toward students with disabilities in the general education classroom. The study examined multiple variables such as gender, race/ethnicity, teaching experience, educators' role, and school size; and the impact of professional development on their attitudes toward inclusion. This study used an explanatory sequential mixed-methods design. Data collection included the Inclusion Attitude Scale for High School Teachers (IASHST), developed by Ernst and Roger, and then focus groups for general education teachers, special education teachers, and support staff in order to triangulate the findings. The results of this study found that general education teachers may have a more negative attitude than special education teachers and support staff. However, it is important to note that members of each focus group described what they considered to be appropriate exceptions to including students with disabilities in the general education classroom.