Cardiac tumors are rare in childhood and can be revealed by arrhythmias. We report the observation of an 18-month-old infant who had an episode of ventricular tachycardia (VT) which resulted in a large intramyocardic tumour diagnosis evocating a left ventricular fibroma. A treatment by amiodarone allowed a stable reduction of the VT. The presence of an intracardiac obstruction or uncontrollable arrhythmias would lead to a surgical resection.