Newborn screening (NBS) in Latin America took its first steps in the mid-1970s. Nevertheless, many years elapsed before it achieved its integration within the public health care system and its systematic and continuous implementation under a programme structure. Latin American countries can be characterized not only by their great geographic, demographic, ethnic, economic and health system diversity, but also by their heterogeneity in NBS activities, which gives rise to variation in degree of organization: countries with optimal fulfilment (Cuba, Costa Rica, Chile, Uruguay); others rapidly expanding their coverage (Brazil, Mexico, Argentina); some others in a recent implementation phase (Colombia, Paraguay, Venezuela, Nicaragua, Peru); others with minimal, isolated and non-organized activities (Guatemala, Dominican Republic, Bolivia, Panama, Ecuador); and finally others without any NBS activities at all (El Salvador, Honduras, Haiti). Despite this disparity, a sustained and significant growth in NBS activities has become evident during the last decade, highlighted by implementation of new programmes, increase in coverage, expansion of NBS panels, increasing involvement of governmental and public health authorities, and integration of NBS teams through scientific societies and External Quality Assurance Schemes. Currently, congenital hypothyroidism (CH) is the most widely screened disease, followed by phenylketonuria, with organized NBS programmes for CH in 14 countries. Other diseases usually included in NBS programmes are screened in a lower rate. Every year, around 11.2 million infants are born in Latin America. During 2005, 49.3% of newborns were screened for CH, indicating that around 5.7 million newborns still did not have access to the benefits of NBS.