Familial hypertrophic cardiomyopathy (HCM) with Wolff-Parkinson-White (WPW) syndrome is extremely rare and associated with a high risk of ventricular tachyarrhythmia and sudden death. We report a familial form of hypertrophic cardiomyopathy associated with Wolff-Parkinson-White syndrome in two siblings 7 and 12-year-old. These patients showed progression to left ventricular dilatation. Early recognition and treatment of such forms can improve such evolution and the risk of sudden death.