Current evidence supports the notion that alterations in intrauterine growth and during the first years of life have a substantial effect on the risk for the development of chronic disease, which in some cases is even higher than those due to genetic factors. The persistence and reproducibility of the phenotypes associated with altered early development suggest the participation of mechanisms that would record environmental cues, generating a cellular reprogramming (i.e. epigenetic mechanisms). This review is an introduction to a series of five articles focused on the participation of epigenetic mechanisms in the development of highly prevalent chronic diseases (i.e. cardiovascular, metabolic, asthma/allergies and cancer) and their origins in the foetal and neonatal period. This series of articles aims to show the state of the art in this research area and present the upcoming clues and challenges, in which paediatricians have a prominent role, developing strategies for the prevention, early detection and follow-up. (C) 2016 Sociedad Chilena de Pediatria. Published by Elsevier Espana, S.L.U.