This research aims to explore the development and use of Technological Pedagogical Content Knowledge (TPACK) in pre-service secondary mathematics teachers. For this multiple case study, evidence of TPACK in three pre-service secondary mathematics teachers was collected during a 15-week semester, during which the pre-service teachers were enrolled in a three-course experience designed to develop an integrated understanding of the use of technology, pedagogy, and content in the teaching and learning of mathematics. Data were collected using a TPACK survey, teaching philosophy statements, lesson plans, student teaching episodes, and interviews, and researchers assigned levels of enacted TPACK and self-reported TPACK. Analysis highlights that the development of pre-service teachers' mathematics TPACK is complex, and pre-service teachers' dispositions about teaching, views of technology, and prior experience in using technology affect their technology use in the classroom. Our results suggest that a model of TPACK development in pre-service teachers is distinct from that used to understand TPACK development among in-service teachers.