The term early childhood intervention (and prevention and development) refers to the specificities of child development and the professional environmental responses to them in the early years of life, which involve many sectors (public education, social, health, etc.) and many professional groups. The understanding of 'early childhood' itself has changed rapidly and now extends from the prenatal period, including the family planning/expansion period, to the child's entry into school. A new element in the system of care and support, in the policy strategies, is the prenatal period, the focus on the family, and the fact that support does not end when children start school. There is a need to design programs with a long-term impact in mind, to 'prepare' for events in later years and stages of life, and to assess the impact of the programs that are in place. The paper summarises some of the basic ideas of early childhood intervention and prevention in a way that takes them forward in time and points to their social impact.