Collaborative ‘at-scale’ models are increasingly being heralded as the answer to the formidable challenges facing general practice. NHS England has signalled that large-scale general practice organisations should form a core component of their vision for new care models set out in the Five Year Forward View. But can these organisations really deliver what is expected of them? This report framed in the project presents findings of an extensive literature review examining the evidence which contributes to the Nuffield Trust’s stream of work on large-scale general practice, including the recently published findings of a 15-month mixed methods research study, Is Bigger Better? Lessons for Large-Scale General Practice.