Intellectual development disorders (IDDs) are a set of development disorders characterized by significantly limited cognitive functioning, learning disorders, and disorders related to adaptive skills and behavior. Previously grouped under the term "intellectual disability," this problem has not been widely studied or quantified in Latin America. Those affected are absent from public policy and do not benefit from government social development and poverty reduction strategies. This article offers a critical look at IDDs and describes a new taxonomy; it also proposes recognizing IDDs as a public health issue and promoting the professionalization of care, and suggests an agenda for research and regional action. In Latin America there is no consensus on the diagnostic criteria for IDDs. A small number of rehabilitation programs cover a significant proportion of the people who suffer from IDDs, evidence-based services are not offered, and health care guidelines have not been evaluated. Manuals on psychiatric diagnosis focus heavily on identifying serious IDDs and contribute to underreporting and erroneous classification. The study of these disorders has not been a legal, social science, or public health priority, resulting in a dearth of scientific evidence on them. Specific competencies and professionalization of care for these persons are needed, and interventions must be carried out with a view to prevention, rehabilitation, community integration, and inclusion in the work force.