Non-invasive diagnostic methods (history, ECG, phonocardiography, exercise testing, Holter monitoring and Doppler echocardiography) were done in 48 persons with mitral valve prolapse (MVP). The aim was to establish possible risk factors for occurrence of ventricular tachycardia (VT) in persons with MVP and to find a possible difference between these risk factors. The possible risk factors for VT are: syncope, negative T wave in the inferolateral ECG leads, longer duration of QT interval, ST devalvation and duration of the ST devalvation, reduction of oxygen consumption evaluated by exercise testing, left ventricular function impairment, polymorphic premature ventricular contractions (PVC's), paired PVC's, larger dimensions of left cardiac chambers, larger surface and thickness of anterior mitral leaflet, extent of mitral regurgitation and higher mitral valve prolapse score. In patients with sustained VT we found higher age, more frequent syncopal attacks, longer QTc interval, more frequent negative T wave in inferolateral ECG leads, deeper ST devalvations, lower oxygen consumption, more prominent left ventricular function impairment, more frequent polimorphic PVC's (more than 10/1000 ventricular complexes), paired PVC's and thicker anterior mitral leaflet than in patients with non-sustained VT. (For all these risk factors is p < 0.01). Non-invasive diagnostic methods could help to identify the patients with mitral valve prolapse at elevated risk for VT.