In a series of 100 patients exhibiting clinical and molecular features of facioscapulohumeral muscular dystrophy (FSHMD), five patients had conduction defects or arrhythmia in the absence of cardiovascular risk factors--namely, intraventricular conduction delay and supraventricular arrhythmia induced by electrophysiologic investigations (two patients), palpitations associated with supraventricular arrhythmia (one patient), severe atrioventricular block leading to pacemaker implantation (one patient), and ventricular tachycardia related to arrhythmogenic right ventricular cardiomyopathy (one patient). Patients with FSHMD may have cardiac involvement.