This report presents the findings of a project that aimed to understand the present state of knowledge of the clinical effectiveness of rehabilitation using the evidence of systematic reviews. Fifty-six systematic reviews covering a variety of disabilities, health problems, diseases and client groups were identified through a literature search. Data was extracted from them in a systematic way and is presented as an evidence table. Two main types of intervention have been evaluated; packages of care and simple interventions, but further important detail about components of the different interventions is often lacking. The report suggests that enough is now known from a clinical effectiveness perspective to move forward significantly in the organisation and provision of rehabilitation. Such is the scale of effects of rehabilitation that this would be expected to have a major impact on the state of services and the health of the population.