This mixed method case study provides insights about how the professional development of middle school teachers is facilitated through their participation in content-focused online communities of practice. A key finding from this research reveals that the online community provided teachers with enhanced opportunities to share ideas, to discuss issues, and to make new connections with colleagues as well as with their principal. In addition, teachers gained curriculum-based knowledge, developed enhanced self-efficacy with respect to implementing technology, and collaborated on the development of interdisciplinary curriculum units. (Contains 5 tables.)