Recent developments in the Department for Education and Skills (DfES) have produced a national pupil database (NPD) that contains information about the attainments of individual pupils. Every child in the country has been allocated a unique pupil number (UPN), which means that the academic progress of individuals can be tracked over time. It is possible to combine data on attainment with the demographic information which is obtained from the pupil level annual schools census (PLASC). These innovations make it possible to combine value added information about pupil progress from one key stage of education to the next with data from the PLASC, which contains pupil background information, to produce a single matched data set. Thus the NPD and the PLASC are able to provide much of the necessary information to explore issues of individual pupil performance over their school careers. Notably, more specific information about the academic achievement of pupils who are described as having special educational needs is now available. Lani Florian, lecturer in inclusion and special educational needs, Martyn Rouse, senior lecturer in inclusion and special educational needs, Kristine Black-Hawkins, senior research associate, and Stephen Jull, research associate, are all based at the University of Cambridge Faculty of Education. In this article, drawing on their work in the 'Inclusion and Achievement Project', they explore the problems and possibilities for researching issues of pupil achievement and inclusion through the use of these new national data sets.