This article explores conceptual and methodological challenges in researching sustainable computer-supported collaborative learning (CSCL) within authentic educational settings. It argues that to investigate the sustainability of CSCL in such settings, we need to understand how new innovations become enculturated as part of educational communities and the shared repertoires and practices of learners and teachers. The potential for Cultural Historical Activity Theory (CHAT) as a relational, dialectical framework for researching collaborative learning is examined. The article argues that, although CHAT is increasingly being used for researching educational settings, it is often employed only descriptively or as a set of guiding principles and the dialectical method, which focuses on emergent contradictions and tensions, is not always fully explored. An integrated conceptual and methodological CHAT framework is proposed for understanding the complex interrelations between discourse, actions and community and as a result how new technological innovations and knowledge creation practices can be appropriated and sustained. This is illustrated through the analytical processes undertaken in a recent empirical study of undergraduates working on an online collaborative research project. The article concludes by arguing that the dialectical method at the heart of CHAT is both unifying and problematizing and could allow us to develop a richer, more integrated and explanatory picture of sustainable CSCL activities.