While iPads and other mobile devices are gaining popularity in educational settings, challenges associated with teachers' use of technology continue to hold true. Preparing preservice teachers within teacher preparation programs to gain experience learning and teaching science using mobile technologies is critical for them to develop positive beliefs and self-efficacy for future technology integration. The purpose of this study was to investigate changes in preservice elementary teachers' technology self-efficacy during their participation in a specialized science content course that utilized a mobile technology-based physics curriculum, Exploring Physics. The Exploring Physics curriculum is available as a hybrid online-offline application running on multiple platforms (iOS, Android, PC/Mac). Participants included 34 preservice elementary teachers who participated in pre- and post-implementation of a technology self-efficacy survey. Data sources also included two focus-group and individual interviews with six participants, weekly classroom observations, and artifacts. Results showed significant positive changes in participants' technology self-efficacy regarding the use of mobile technologies in science teaching. Factors that supported participants' technology self-efficacy included: (a) firsthand experiences with iPads, (b) enhanced science content understandings, (c) high interactivity and engagement, and (c) instructor modeling the use of technology. Findings have implications for preservice teacher preparation for technology integration in science teaching.