There is a widely held belief that teaching assistants (TAs) lighten teachers’ workloads, support learning and increase the level of pupil engagement, thus securing inclusion for pupils with special needs and raising standards. The National Agreement on workforce reform sets out plans to free teachers to focus on teaching and learning, and to develop the roles of TAs in schools; new teachers need to be prepared for working as part of a team. This requires information about the current roles of teaching assistants, and where they are most effective. The report will be of interest to policy-makers, initial teacher trainers, school managers, teachers and teaching assistants. This systematic review was published by EPPI-Centre in 2007.Systematic reviews aim to find as much as possible of the research relevant to the particular research questions, and use explicit methods to identify what can reliably be said on the basis of these studies.