This paper presents a general rationale for investing in early childhood development (ECD) in Latin America that derives from scientific evidence about the importance of the early years in the formation of intelligence, personality, and social behavior. This rationale argues that the economic returns of ECD programs can be quite high (through increased productivity, cost savings, and potential employment effects), that inequalities can be moderated, and that children have a right to develop in a healthy way. Evidence from Latin America and elsewhere shows that programs designed to improve children's health, nutrition, and psychological condition in their preschool years can affect significantly children's development and readiness for school. A sound program strategy for ECD should include: (1) an initial assessment of the condition of children; (2) a search for ways to integrate child development components into ongoing education, health, and nutrition programs; (3) an emphasis on training and communication; (4) collaboration among governments, non-governmental organizations, and communities; (5) a process of carrying out evaluation and research; and (6) the establishment of an appropriate organizational strategy. An appendix contains case studies of projects conducted in Colombia, Turkey, and the Philippines. Contains 61 references. (MDM)