The principal common feature of home visiting programs is that trained child development or community agents meet with mothers or parents on a regular basis to observe the interactions between caregivers and their children, and to provide practical guidance on how to interact with them. At the core of these visiting programs is a detailed curriculum, which contains key topics of child health and development to be covered at each home visit. Detailed information and supporting materials for each session have been developed for the original Jamaica study and are currently being adapted to the Brazilian context. In this project, we will assess the effectiveness and cost-effectiveness of the newly adapted home visiting programs in the poor urban context of Sao Paulo, Brazil. Given that Brazil's middle and upper income children already benefit from a range of early childhood care services, our focus will be low-SES families. Brazil currently offers a free health care system (SUS), which is primarily used by the low SES groups, according to the latest estimates 55.6 percent of urban households in Sao Paulo - these households will be the target population for the interventions, a group of 400 low SES mother-child dyads from Sao Paulo's western region.