Preparing preservice teachers to use computers effectively in teaching and learning is fundamental for significant educational reform. Often, preservice teachers possess traditional beliefs about teaching and learning and view the computer as a device to support traditional education. Because educational reform is, in part, contingent on the preparation of the next generation of teachers, it is imperative that teacher educators design and implement instructional strategies that help preservice teachers to develop comprehensive conceptions about classroom computer use. The purpose of this case study was to explore and examine the effects of a conceptual change-based instructional unit on preservice teachers' conceptions about teaching, learning, and the role of the computer in the classroom.;The data collected throughout the Instructional unit indicated that the extent of conceptual change experienced by each participant was unique based upon their existing conceptions, individual learning experiences, and motivation toward the alternative conception being taught. Based upon the analysis of each participant's progression through the conceptual change process and the collective data analysis, the instructional unit was effective in creating the conditions necessary for conceptual change to occur.