The purpose of this phenomenological study was to explore how secondary co-teachers' experiences influenced their attitudes when co-teaching students with a reading disability in the co-taught classroom. A total of seven secondary co-teachers were selected to represent the population for this study. Bandura's (1977) "self-efficacy theory" provided the framework to synthesize co-teachers' perceptions of their experiences influencing their attitudes and self-efficacy when teaching students with a specific learning disability in reading. An interview protocol was the sole basis for the data collection instrument. This study sought to explore how secondary co-teachers describe their experiences in the co-teaching classroom, influencing their perceptions of their attitudes when co-teaching students with a specific learning disability in reading. The phenomenological method ensured that the lived experiences of the phenomenon were discussed in depth to uncover the details of the co-teachers' descriptions of their experiences influencing their attitudes toward teaching students with a reading disability. The three research questions aligned with Bandura's (1977) self-efficacy theory of mastery experiences and vicarious experiences guided the interview questions. The co-teachers' descriptions were coded and organized into seven themes and 13 sub-themes. The emerging themes provided two recommendations for practice in supporting co-teachers' experiences in the co-teaching classroom to allow better outcomes for secondary students with a reading disability. The key findings from this study may contribute to educational research by raising awareness of secondary co-teachers' perceptions of their experiences influencing their attitudes toward teaching students with a reading disability. [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.]