Traditional general practice is changing. Three-quarters of practices are now working collaboratively in larger-scale organisations – albeit with varying degrees of ambition and organisational integration. Policy-makers and practitioners have high hopes for these organisations and their potential to transform services both within primary care and beyond. But can we be confident that they can live up to these expectations? This report presents findings of an extensive literature review on the subject of large-scale general practice, and contributes to a stream of work by the Nuffield Trust in this area, details of which can be found at: www.nuffieldtrust.org.uk/large-scale-general-practice .