The prevention of unexpected cardiac events in the young remains elusive. Among them, some are lethal. Early identification of life-threatening arrhythmogenic disorders which often manifest in infancy, childhood or even later, may allow initiation of effective preventive therapies. A large prospective study has indicated that some infants with prolongation of the QT interval in the first week of life died suddenly, and would have previously been labelled as victims of the sudden infant death syndrome. Furthermore, in infants with this diagnosis, post-mortem molecular screening has revealed the presence of the long QT syndrome. As an evolution of this background, some European countries have begun to consider the possibility of introducing in their National Health Services the performance of an electrocardiogram during the first month of life in all newborns, as part of a programme for cardiovascular screening. Most adult cardiologists, however, have no or minimal experience with electrocardiograms recorded in infants. Accordingly, the European Society of Cardiology has instituted a Task Force with the objective of creating guidelines for the interpretation of the neonatal electrocardiogram, focusing on the most clinically relevant abnormalities and on the ensuing options for management and referral. The main objective of the present document is to provide adult cardiologists with a practical approach to neonatal electrocardiography, and paediatricians and neonatologists with a tool that should facilitate medical interaction on cardiologic issues. There are important differences between neonatal and adult electrocardiograms. When a cardiologist examines the electrocardiogram of an apparently normal and healthy infant, the focus has to be on distinguishing between patterns that should cause no alarm, and those that require action or additional investigations. To provide clues for this distinction has been the main objective of the members of this Task Force. Whenever possible or appropriate, we have also suggested steps in management.