e-Portfolios are a form of authentic assessment with formative functions that include showcasing and sharing learning artifacts, documenting reflective learning processes, connecting learning across various stages and enabling frequent feedback for improvements. This paper examines how e-portfolios take up these formative roles to support productive learning. Qualitative findings from interviews with selected first-year undergraduate students at a higher education institution in Hong Kong are reported concerning students' experiences of constructing e-portfolios as assessment tasks. As part of an institutional teaching and learning initiative, e-portfolios were incorporated into three core courses for first-year students. The findings reveal that several conditions necessary to foster productive learning were missing in students' experiences: strengthened formative role of e-portfolios through coherent assessment design; encouragement for students' pursuit of authentic tasks to develop learning interests; engagement of students in reflective and self-regulative learning as an essential learning process; provision of constructive feedback for sustained learning support; and support for students' autonomy through facilitation of collaborative knowledge building. By explicating how the lack of these conditions impeded students' active involvement in e-portfolio tasks and suggesting relevant strategies for teachers at the institution in question, this paper offers implications for harnessing information and communication technology (ICT) to support students' productive learning. Copyright © 2015 British Educational Research Association.