The classic features of Wolff-Parkinson-White syndrome developed in a 49 year old man after he was given the heart of a donor who had had a normal electrocardiogram. The recipient showed type A pre-excitation on the surface electrocardiogram and clinically important paroxysmal supraventricular tachycardia. An electrophysiological study showed a left sided accessory pathway and dissociation between donor and recipient atrial activity during tachycardia. The arrhythmia was controlled by flecainide.