This study explored three high school agriculture teachers' perceptions of science, technology, engineering, and mathematics (STEM) integration through interviews. The approach was constructivist and data were analyzed according to the framework of integrated STEM education presented in a National Academy of Sciences report. Each participant agreed to complete three interviews that first investigated past experiences, then present perceptions, and lastly reflections on meaning. A total of about six hours of interview data were analyzed using the constant comparative method. Teacher perceptions were outlined individually and then compared. The teachers shared similar perceptions related to time constraints, the effects of STEM integration, concerns about rapport with students, how agricultural education has changed, and curricular resources. Perceptions aligned well with the framework of integrated STEM education because teachers described increased student interest, motivation, and career-readiness due to agriculture programs, and these perceptions were in some cases supported by non-agriculture teachers. Misconceptions of STEM education included incomplete definitions of engineering education and viewing the use of instructional technology as STEM education. Teacher educators may benefit from increased insight into the perceptions of veteran teachers.