Children’s health affects the future of Europe – children are citizens, future workers, parents and carers. Children are dependent on society to provide effective health services (UN Convention on the Rights of the Child). Models of child primary health care vary widely across Europe based on two broad alternatives (primary care paediatricians or generic family doctors), and a variety of models of school health and adolescent direct access services.There is little research to show which model(s) are best, implying that some are inefficient or ineffective, with sub-optimal outcomes.MOCHA will draw on networks, earlier child health projects and local agents to model and evaluate child primary care in all 30 EU/EEA countries. Scientific partners from 11 European countries, plus partners from Australia and USA, encompassing medicine, nursing, economics, informatics, sociology and policy management, will:• Categorise the models, and school health and adolescent services• Develop innovative measures of quality, outcome, cost, and workforce of each, and apply them using policy documents, routine statistics, and available electronic data sets• Assess effects on equality, and on continuity of care with secondary care.• Systematically obtain stakeholder views.• Indicate optimal future patterns of electronic records and big data to optimise operation of the model(s).The results will demonstrate the optimal model(s) of children’s primary care with a prevention and wellness focus, with an analysis of factors (including cultural) which might facilitate adoption, and indications for policy makers of both the health and economic gains possible. The project will have a strong dissemination programme throughout to ensure dialogue with public, professionals, policy makers, and politicians. The project will take 42 months (36 of scientific work plus start up and close), and deliver major awareness and potential benefit for European children’s health and healthy society.