The paper examines the rationale and the uses of portfolios in initial teacher education. This rationale is then applied to explore the development and implementation of the Professional Development Portfolio (PDP) as an integral part of the initial teacher education programme offered by the Faculty of Education, University of Malta. The paper considers the responses of students and lecturers to this mode of assessment; in particular, how the tensions between the formative and summative functions of portfolios were experienced and responded to at institutional level. The paper is the result of the debates and discussions among the three authors. Deborah Chetcuti and Grace Grima were directly involved in the development of the assessment innovation, Patricia Murphy was a visiting academic and external examiner during the period.