This chapter explores the use of portfolios in assessment, starting with a general overview of the nature of assessment portfolios, then moving on to their use within technology education for developing and assessing capability. I start by considering their early use in public examinations in England and reasons why they were introduced. From this I explore issues presented by using portfolios, their potential and their problems. I draw on a range of research and development projects, mainly from within technology education, then present a case study of portfolio development from research at Goldsmiths, University of London, and use this as a basis for exemplifying the potential of digital portfolios. Finally, I provide hopeful but cautious guidance, drawing from the success stories, the findings, and the concerns raised through the chapter.