Background. The Cochrane Collaboration is an international organisation that aims to help people make well-informed decisions about healthcare by preparing, maintaining and promoting the accessibility of systematic reviews of the effects of healthcare interventions. This paper briefly summarises the output of the Cochrane Stroke Group in relation to evaluating different forms of the organisation of services for patients with stroke. Methods: A survey of randomised controlled trials and systematic reviews (and meta-analyses) of randomised controlled trials. Results: Issue 2 of the Cochrane Library 2002 includes 1,377 completed systematic reviews and 1,055 protocols for reviews in progress. The Cochrane Controlled Trials Register included 343,270 reports of randomised or controlled clinical trials. The Cochrane Stroke Review Group had contributed 63 completed systematic reviews, 29 protocols of reviews in progress, and 4,396 reports of stroke trials. The main published reviews relevant to entire services related to: stroke units; services for helping acute stroke patients avoid hospital admission; services for reducing duration of hospital care for acute stroke patients; care pathways for stroke. Main Conclusions: There has been a rapid recent growth in the evidence base on stroke care. Systematic reviews of several aspects of stroke services are now published and other reviews are in progress. For areas where no reviews have been completed, the Cochrane Library includes a substantial number of individual randomised trials evaluating the effects of specific services and components of services. Copyright (C) 2003 S. Karger AG, Basel.