The growing popularity of mobile technologies in educational settings, from grade schools through college, has prompted science educators to prepare preservice teachers to successfully integrate technology into science teaching. This mixed-methods study explores the effectiveness of a mobile technology-based physics curriculum, Exploring Physics, on preservice elementary teachers' technology self-efficacy. Participants included 67 preservice elementary teachers enrolled in a specialized physics content course at a large public university in the United States. The experimental group (N = 34) used the Exploring Physics curriculum on iPads, and the comparison group (N = 33) used a hardcopy version of a similar curriculum. Data sources included a technology self-efficacy survey administered as pre-and posttests, focus group and individual interviews with 24 participants at two time points, weekly classroom observations, and artifacts. Data analyses included repeated measures analysis of variance and posthoc t tests with Bonferroni adjustments and grounded theory techniques.The results showed significant positive changes in the experimental group participants' technology self-efficacy.In contrast, there was a significant decrease in the comparison group participants' technology self-efficacy.