Real time 3-dimensional (3D) echocardiography (RT-3D) may be a useful tool in evaluation of patients with coronary artery disease, left ventricular apical thrombi, valvular disease, in guiding intracardiac catheter placement and mitral valvuloplasty. RT-3D, which has recently become widely available, provides dynamic pyramidal data structures that encompass the entire heart and allows four-dimensional assessment of cardiac anatomy and function. It has been shown that this technique is very precise in determination of LV volume, mass and EF measurement and is well correlating with MRI (4-6). Mild changes in LV volume, LV mass and function occur during acute cardiac rejection. This very sensitive technique for assessment of regional volumetric changes has not yet been used for heart transplants monitoring.