Much has already been written about the portfolio-based approach to learning. The first part of this paper will consider key messages from the literature and argue that an understanding of portfolios can only follow from consideration together of the three issues of content, purpose and assessment. Assessment of portfolios will then be discussed further in the context of the educational philosophy that underpins what it means to practise as a reflective professional. Practical aspects of design, implementation and acceptability are dealt with throughout.