The concept of inclusive education stressed the classroom conditions for students with disabilities (SWDs) as they strive to achieve their maximum learning potential alongside their nondisabled peers. The feat proved to be challenging as teachers implement instructions that meet federal laws, district guidelines and policies, schools' visions, and parental involvement. Using Vygotsky's sociocultural theory and Bandura's social cognitive theory, the purpose of this case study was to explore high school chemistry teachers' knowledge, perceptions, and practices of inclusion in the classroom. The research questions were used to explore teachers' understanding of inclusion, the perceived strategies for a successful inclusive classroom, and the inclusive practices utilized in the classroom. I have used semi-structured interviews, class observations, and comparative analysis of lesson plans to collect information. Data were gathered from a purposeful sample of two high school chemistry teachers who have experienced working with SWDs through the individualized education program (IEP). The themes that emerged from this study included "differentiated instructions," "high(er) expectations," "hands-on learning," "modified lessons," "accommodations," "limited teaching opportunities," "professional development for inclusion," "resources," and "inclusive for all." This study will provide school administrators with a deeper understanding of the professional development needs of teachers. Recommendations for future research include having a larger sample size to achieve data saturation and provide evidence of inclusive education in the district. In addition, designing and implementing an adaptive professional development that focuses on addressing the needs of all learners would be advantageous. [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.]