Visualization of the cardiac anatomy becomes more and more important as the complexity of interventions increases. Intracardiac echocardiography (ICE) provides good depiction of cardiac soft tissue structures and has become an important tool in today's cardiology. It has been shown to be valuable during many ablation procedures for supraventricular and ventricular arrhythmias. ICE has been used for monitoring catheter placement, observing catheter-tissue contact and lesion formation as well as titrating ablation energy. The rate of complications could be reduced, outcome of procedures improved and radiation exposure decreased. Even more, new therapy strategies have been evaluated based on ICE and it has also been used in the setting of three- dimensional imaging and image integration.