Ventricular arrhythmias represent one of the most essential problem in paediatric cardiology because of different aetiology and hemodynamic consequences, sometimes leading to cardiac sudden death. Premature ventricular contractions are often caused by an underlying disease e.g. myocarditis, cardiomyopathy, tumours of heart, myocardial ischemia, congenital and acquired heart diseases. Ventricular arrhythmia is common after cardiac surgery, particularly in specific cardiac abnormalities, such as tetralogy of Fallot. Simple ventricular arrhythmia may be seen in routine resting electrocardiograms in children with normal cardiac findings. There are usually isolated monomorphic premature ventricular contractions, sometimes in the form of couplet-triplet but even nonsustained ventricular tachycardia can be recorded. This paper presents case of asymptomatic ventricular arrhythmias in a 17-year-old male patient with signs of hibernating myocardium in myocardial perfusion scintigraphy.Authors pay attention that even though ventricular arrhythmia seems to be innocent, arrhythmogenic substratum always should be searched.