Pediatric arrhythmology deals with studying of frequency and regularity of heart rhythm disorders in childhood. Rhythm disturbances (dysrhythmias, arrhythmias) occur as a result of disturbances in the creation or conduction of stimuli in the specific or working musculature of the heart. Simplifying the knowledge of everyday work on pediatric arrhythmias, they can originate from the atria of the heart when we speak about supraventricular arrhythmias or from the heart chambers when we talk about ventricular arrhythmias. There are currently three major problems that burden pediatric cardiologists and pediatric arrhythmologists, and which are the focus of interest in pediatrics as a whole. These are primarily sudden cardiac death in children (SCD), fetal arrhythmias (FA) and postoperative-incisional arrhythmias (IA). The development of pediatric arrhythmology is imperative in the development of pediatrics and pediatric cardiology.