Background. Inclusive education/mainstreaming is a key policy objective for the education of children and young people with special educational needs (SEN) and disabilities.

Aims. This paper reviews the literature on the effectiveness of inclusive education/mainstreaming. The focus is on evidence for effects in terms of child outcomes with examination also of evidence on processes that support effectiveness.

Samples. The review covers a range of SEN and children from pre-school to the end of compulsory education.

Method. Following an historical review of evidence on inclusive education/mainstreaming, the core of the paper is a detailed examination of all the papers published in eight journals from the field of special education published 2001-2005 (N=1373): Journal of Special Education, Exceptional Children, Learning Disabilities Research and Practice, Journal of Learning Disabilities, Remedial and Special Education, British Journal of Special Education, European Journal of Special Needs Education, and the International Journal of Inclusive Education. The derived categories were: comparative studies of outcomes: other outcome studies; non-comparative qualitative studies including non-experimental case studies; teacher practice and development; teacher attitudes; and the use of teaching assistants.

Results. Only 14 papers (1.0%) were identified as comparative outcome studies of children with some form of SEN. Measures used varied but included social as well as educational outcomes. Other papers included qualitative studies of inclusive practice, some of which used a non-comparative case study design while others were based on respondent's judgements, or explored process factors including teacher attitudes and the use of teaching assistants.

Conclusions. Inclusive education/mainstreaming has been promoted on two bases: the rights of children to be included in mainstream education and the proposition that inclusive education is more effective. This review focuses on the latter issue. The evidence from this review does not provide a clear endorsement for the positive effects of inclusion. There is a lack of evidence from appropriate studies and, where evidence does exist, the balance was only marginally positive. It is argued that the policy has been driven by a concern for children's rights. The important task now is to research more thoroughly the mediators and moderators that support the optimal education for children with SEN and disabilities and, as a consequence, develop an evidence-based approach to these children's education.