Atrial tachycardias represent the second front of atrial fibrillation (AF) ablation. They are frequently encountered during the index ablation for patients with persistent AF and are common following ablation of persistent AF, occurring in half of all patients who have had AF successfully terminated. An atrial tachycardia is rightly seen as a failure of AF ablation, as these tachycardias are poorly tolerated by patients. This article describes a simple, practical approach to diagnosis and ablation of these atrial tachycardias.