Percutaneous transcatheter aortic valve implantation (TAVI) is an evolving interventional therapy for high-risk, non-surgical patients with severe, symptomatic aortic valve stenosis (AS). As a standard procedure, 2D transesophageal echocardiography has been used for the preinterventional assessment of the native valve and measurement of the aortic annulus as well as for intraprocedural guidance. Recently, a new matrix array, transesophageal probe for real-time three-dimensional echocardiography (RT3D-TEE) has been introduced. We applied this new technique to monitor percutaneous aortic valve implantation and described our initial experiences with this method in patients undergoing TAVI. We hypothesized that RT3D-TEE provides improved evaluation of the native aortic valve and annulus dimension due to unlimited scan plane orientation. This new technology should also enable accurate guiding of percutaneous cardiac interventions by providing immediate information on prosthesis position and function in real-time. In our preliminary clinical experience real-time three-dimensional transesophageal echocardiography (RT3D TEE) was demonstrated to provide improved guiding of percutaneous aortic valve replacement by superior spatial visualisation of the cardiac structures and facilitated the detection of procedure-related complications. Due to the advantages of real-time 3D TEE monitoring, this technique might improve the outcome of patients treated with percutaneous aortic valve replacement.