Ventricular arrhythmias with LBBB morphology are often seen in ECG findings of healthy persons. The most common ones are premature ventricle complexes with the morphology usually seen in arrhythmias of right ventricle origin, but their shape in certain leads helps us in finding the precise location of the arrhythmia focus. The discovery of ventricular tachycardia and ventricular fibrillation is rare. The main causes are idiopathic arrhythmias or those who arise from the structurally normal heart. A small number exists within some genetic disorders of the heart such as arrhythmogenic right ventricular car-diomyopathy and Brugada syndrome. With the increase of the number of cardiosurgical procedures in children, especially after the correction of the tetralogy of Fallot, the risk of arrhythmia development within the scar tissue is rising. Although those conditions are rare in the right ventricle, for the mentioned reasons, the probable cause of right ventricle arrhythmias could also be right ventricle myocardial infarction and Chagas disease. The biggest number of arrhythmias originate from the right ventricle outflow tract, relating to its embryonic development. Also, with the same etiologic assumption, the appearance of arrhythmias from the tricuspid annulus is almost as common as the especially unpredictable arrhythmias from the right ventricular papillary muscles. Although idiopathic ventricular arrhythmias share a good prognosis, it is very important to recognize and exclude other causes of arrhythmias because they are linked to 10-30% of all causes of sudden cardiac death in the young population. In many cases, it is very difficult to choose the right treatment option. As choosing just conservative treatment is often not sufficient, RF ablation should be done or an AICD implanted in the attempt to prevent the development of the malignant arrhyth-mias and sudden cardiac death. Never-theless, since existing algorithms for setting the diagnosis of these diseases are often failing, even today many patients remain underrecognized and their diagnosis is established when it is already too late.