A number of interventional procedures based on the transseptal puncture (TSP) have been developed in recent years. The increasing number of interventional procedures, as well as the use of large-bore sheaths and complex devices, has led to improvements in technique and equipment. The combined use of fluoro-scopy and of transoesophageal echocardiography (TEE) has increased safety and precision. However, TSP still represents a tricky procedure, which may become even more difficult in cases of challenging interatrial septa, and life-threatening complications may occur. Consequently, an in-depth knowledge of procedural steps, equipment, echocardiographic views, fossa ovalis anatomy and how to manage the most frequent complications is critical to performing a successful TSP.