Background: Catheter ablation has been used to manage supraventricular arrhythmia in children since 1990. This article reviews the history of catheter ablation used to treat arrhythmia in children and discusses new frontiers in the field. We also address ablation in adult patients with a history of congenital heart disease (CHD) that was diagnosed and initially treated in childhood.; Methods: We conducted an evidence-based literature review to gather available data on ablation for supraventricular tachycardia in children and adult patients with CHD.; Results: Ablations can be performed safely and effectively in children. Complication rates are higher in children < 4 years and < 15 kg. In one study, the overall success rate of radiofrequency ablation in pediatrics was 95.7%, with the highest success rate in left free wall pathways (97.8%). Recurrence was higher in septal pathways. Cryoablation has been reported to have a 93% acute success rate for atrioventricular (AV) nodal reentrant tachycardia and septal pathways with no risk of AV block and a 5%-9% risk of recurrence. Three-dimensional mapping, intracardiac echocardiography, remote magnetic navigation, and irrigated catheter ablation are new technologies used to treat pediatric and adult patients with CHD. The population of adult patients with CHD is growing, and these patients are at particularly high risk for arrhythmia. A paucity of data is available on ablation in adult patients with CHD.; Conclusion: Electrophysiology for pediatric and adult patients with CHD is a rapidly growing and progressing field. We benefit from continuous development of ablation techniques for adults with structurally normal hearts and have the unique challenge and responsibility to ensure the safe and effective application of these techniques in the vulnerable population of pediatric and adult patients with CHD.