catheter ablation is an established therapeutic option for the treatment of cardiac arrhythmias. Despite technical advances, catheter ablation is still associated with potentially severe complications, whose incidence is up to 5%. Structured and goal-oriented pathways to manage particularly acute, periprocedural complications are therefore required. It is essential for interventional electrophysiologists to recognize potential complications early and to master the necessary measures safely right from the beginning of their training. This chapter summarizes the incidence and risk factors for common and serious periprocedural complications such as vascular complications, pericardiac tamponade, and thromboembolic events in the context of catheter ablation, explains strategies for complication prevention, and complication management.