The purpose of this study was to explore preservice special education teachers' experiences within an instructional material development project for students with disabilities during a semester-long technology integration course. Data were collected from 61 preservice special education teachers through an open-ended questionnaire, instructional design reports, and instructional materials. The findings indicated that working with students with disabilities in a real-life environment helped the preservice teachers realize the importance of assistive technology in education to support these students' needs. This experience also helped the teachers to ascertain what barriers may exist to assistive technology use in education, such as insufficient technology knowledge and skills, and inadequate infrastructure of classrooms, etc. The preservice teachers emphasized that following an instructional design process facilitated the development of effective instructional materials. They also stressed that the instructional material development project contributed to their professional development in different ways, such as practical skills through real-life experiences and technology-related skills.