We describe a 9-year old patient with arrhythmogenic right ventricular dysplasia. The patient presented with sustained ventricular tachycardia in an apparently normal heart. The diagnosis was suspected by the electrocardiographic morphology of the tachycardia and definitive diagnosis was made by right ventricular angiogram, echocardiogram and the ventricular endomyocardial biopsy findings (replacement of myocardial by adipose tissue and fibrosis). We believe that this condition may be a common etiology of ventricular tachycardia with left bundle branch block conduction pattern in children with otherwise normal hearts.