This study presents a refined technological pedagogical content knowledge (also known as TPACK) based instructional design model, which was revised using findings from the implementation study of a prior model. The refined model was applied in a technology integration course with 38 preservice teachers. A case study approach was used in this implementation study. Data were collected from the participants' discussion worksheets and lesson plans, along with associated artifacts and the researchers' field observation notes. Data analysis results revealed that (a) preservice teachers' had an entry-level understanding of TPACK through discussions on the meaning of TPACK and evaluations of technology-integrated teaching examples; (b) designing several technology-integrated lesson plans improved preservice teachers' teaching-related knowledge and facilitated their TPACK learning; and (c) preservice teachers' use of technology was more teacher centered than student centered. Findings, suggestions, and future research possibilities are also discussed.