This study examines the ways in which all nine middle school teachers in a private school for boys in the United States integrated mobile devices with content and pedagogy 4 years into the implementation of a one-to-one initiative. It also examines teacher perceptions of the benefits and challenges related to the implementation of mobile devices in real classroom contexts. Data were collected from multiple sources including teacher lesson plans, classroom observations, and interviews. Data collection and analysis were situated in the framework of Technological Pedagogical Content Knowledge (TPACK), which is used to examine teacher knowledge and observed evidence of TPACK during classroom instruction. Results indicated that teachers were able to draw connections among mobile devices, content, and pedagogy to support student experiences. Results, however, indicated variability in teacher practice and pointed to the important role of continuous professional learning. Findings have implications for researchers and practitioners involved in the design and implementation of one-to-one initiatives.