The incidence of idiopathic ventricular tachycardia is scarce; however, it is the most common type of ventricular tachycardia in previously normal children. Left posterior fascicular ventricular tachycardia is one of them, and many times it is mismanaged as paroxysmal supraventricular tachycardia. The characteristic features of this arrhythmia are a monomorphic tachycardia, right bundle branch block, and superior axis. This type of arrhythmia is highly sensitive to verapamil, even in infancy, but refractory to adenosine or amiodarone. As nonrecognition of this condition can be fatal, it should be identified early.