Scholarship addressing technological pedagogical content knowledge (TPCK or TPACK) has examined how to develop, apply, and assess it in diverse educational settings and content areas. During the last 12 years, multiple ways to understand this knowledge and support its development have emerged, generating approximately 1,200 publications that utilise the construct, impacting the practice of postsecondary faculty, administrators, and others invested in meaningful educational uses of technology. Perhaps inevitably, TPACK’s enthusiastic reception and rapid dissemination have generated multiple points of divergence, which in turn need further study; especially the construct’s accurate measurement and validation; how to assist preservice and in-service teachers’ TPACK development; contextual influences upon teachers’ TPACK; and the relationship of TPACK-based knowledge to teachers’ decision-making and action. Given the widespread diffusion of TPACK, research focusing on these and related issues will help to determine the direction of future post-secondary learning and teaching with technologies. Therefore, this special issue of AJET addresses future directions in TPCK/TPACK research and development.