The main claim of this book is that writing is an act of identity in which people align themselves with socio-culturally shaped subject positions, and thereby play their part in reproducing or challenging dominant practices and discourses, and the values, beliefs and interests which they embody. The first part of the book reviews recent understandings of social identity, of the discoursal construction of identity, of literacy and identity, and of issues of identity in research on academic writing. The main part of the book is based on a collaborative research project about writing and identity with mature-age students, providing: a case study of one writer’s dilemmas over the presentation of self; a discussion of the way in which writers’ life histories shape their presentation of self in writing; an interview-based study of issues of ownership, and of accommodation and resistance to conventions for the presentation of self; linguistic analysis of the ways in which multiple, often contradictory, interests, values, beliefs and practices are inscribed in discourse conventions, which set up a range of possibilities for self-hood for writers. The book ends with implications of the study for research on writing and identity, and for the learning and teaching of academic writing.