Despite steady progress in research in technology-enhanced learning (TEL), the translation of research findings and technology into educational practices falls short of expectations. We present five Areas of Tension which were identified and evaluated in an international Delphi study on TEL. These tensions might impede a more comprehensive inclusion of information and communication technologies (ICT) in educational settings. The Delphi study was embedded in the European Network of Excellence STELLAR (Sustaining Technology Enhanced Learning LArge-scale multidisciplinary Research). Five Delphi rounds were conducted to identify Areas of Tension and Core Research Areas in TEL. An Area of Tension opposes two conflicting views on a certain technological development regarding the future of TEL. In the present article we describe the design of the Delphi study and report the results regarding the Areas of Tension. These areas were identified by collecting visionary statements on the future of TEL (Round 1) and by having 230 international experts evaluate those statements (Round 2). The emerging tensions were integrated into five Areas of Tension (Round 3) and evaluated by 569 international experts on several dimensions for their significance for TEL and TEL research (Round 4). The identified areas concern a) data tracking for personalized learning versus data privacy, b) the spreading of technology reducing the digital divide versus even increasing it, c) ubiquitous learning opportunities versus critical and focused processing of information, d) continuous innovation in the classroom versus approved practices, and e) individualized versus standardized learning paths. (Contains 7 tables and 3 figures.)