Rationale Trials of new treatments for neurological disorders like stroke require imaging as part of the patient assessment, but need to be large enough to obtain reliable results if treatment effects are likely to be modest. However, multi-centre trials use many different scanners in different hospitals and present complex problems for image data collection, interpretation and analysis and long-term secure archiving. Aims NeuroGrid aims to develop and test grid technologies for collecting, analysing and interpreting, and secure archiving of neuroimaging data for large multicentre trials in common neurological and psychiatric disorders. Design A 3-year multicentre consortium of clinicians, neuroimaging centres and e-scientists are designing a Grid storage network, mechanisms for uploading, curating and retrieving image and metadata, combining image data from different scanners and an analysis tool box. Three clinical exemplars stroke, dementia and psychosis – provide the data and ‘real-world’ clinical trial applications, and a set of specific and typical problems encountered with image data in multicentre trials for NeuroGrid to address. The stroke exemplar is using image data from two multicentre stroke trials: Third International Stroke Trial and Efficacy of Nitric Oxide in Stroke. Outcomes The final product is intended to appear as an integrated capability consisting of services, both database and analyses, accessed through simple portals. These will include image submission, automated scan quality control, appropriate metadata linkage, streamlined image review and coding tools and long-term secure storage for future multicentre stroke trials.