In Italy, the nationwide newborn screening programme for congenital hypothyroidism (CH) represents an integrated approach to the disease including screening tests, diagnosis, treatment, follow up and nation-wide surveillance of the disease. The latter is performed by the Italian National Registry of Infants with Congenital Hypothyroidism (INRICH). The INRICH is a population-based Registry, this implies that results obtained in the analyses conducted on the data collected in the INRICH are highly representative, can be easily used to improve the health of CH children, and provide information critical to understanding the etiology of the disease. Over the years, the INRICH has contributed: i) to improve procedures for diagnosis, treatment and follow-up of affected babies, by identifying critical points in screening program procedures; ii) to estimate the incidence of CH and the prevalence of the different forms of the disease (thyroid dysgenesis, normally located and shaped thyroid) in our country; iii) to provide a unique opportunity for research into this condition given the large amount and the high quality of information collected in this registry.