Child public health policy developments have been driven by the development of the science of life-course epidemiology and the realisation that early life experiences are key determinants of health and disease prospects, especially avoidable chronic disease. Control of childhood infections has been a great success with the recent and extraordinary exception of measles, mumps and rubella. The prevention of accidents and avoidable chronic diseases remain key challenges. The chapter focuses on preventing avoidable chronic diseases from an early age through the promotion of positive health behaviours and the development of a supportive health-promoting environment. There are major health inequalities in the distribution of chronic diseases between social groups. The chapter identifies some of the key public health challenges in England and the policy implications. The prevention of avoidable chronic diseases is one of the biggest contemporary public health challenges facing society.