Atrial flutter is one of the most common supraventricular arrhythmic diseases and occurs with an incidence of 88/100,000. The high risk for thromboembolic events is similar to that for atrial fibrillation and also has the risk for fast conduction to the ventricle. Pharmacological treatment is not significantly effective. Catheter ablation of common atrial flutter offers an alternative with a high quality outcome ranging from 90-96% and a low recurrence rate of 2-6%. Radiofrequency catheter ablation of the cavotricuspidal isthmus is an established treatment for common atrial flutter. Modern techniques like cryo-ablation show nearly the same results and will be an alternative to the RF ablation in the future.