The purpose of this qualitative phenomenological study was to explore the perception and lived experiences of general education teachers and special education teachers in a co-taught classroom. The study looks at the effects of targeted professional development and teachers' attitudes in co-taught classrooms at the high school level in Pennsylvania. This study is framed by the following research questions: (a) How do general education and special education teachers describe the essences of their experiences with co-teaching? (b) How do the attitudes of general education teachers and special education teachers affect the co-teaching environment at the high school level? and (c) Can a Professional Learning Community (PLC) focused on co-teaching strategies improve the perceptions of teachers toward one another and the roles each plays in the classroom? The conceptual framework that provides a foundation for this study is based on the researcher's experience over the past 17 years as a special educator in the co-teaching classroom. Looking through a social constructivist lens, the three streams that form the foundation for the current research include: legislation, effective co-teaching models, and strategies within a co-taught classroom. For the qualitative research, three dual certified teachers, twelve general education teachers, and six special education teachers participate in interviews, focus groups, journaling, and observations. Once data are collected, transcriptions explore themes of the lived experiences of all the general education teachers and special education teachers within the co-taught classroom. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]