This paper considers how some secondary schools in England have been able to respond to the conflicting demands of school improvement policies, as measured by high academic standards and the inclusion of pupils with special educational needs. It begins with a discussion of the context in which all English schools are currently operating and a summary of the extent to which research on school effectiveness and school improvement has influenced research on inclusion and vice versa. Key findings from our work in secondary schools committed to inclusion are presented and discussed in light of teacher, subject department and whole school responses to pupil diversity. The paper concludes with a conceptualisation of inclusive schools as those that meet the dual criteria of enrolling a diverse student population and improving academic standards for all.