Three months after orthotopic cardiac transplantation, a 46-year-old man developed paroxysmal supraventricular tachycardia. Electrophysiological investigation of the arrhythmia led to the diagnosis of an atrioventricular reentrant tachycardia involving a left lateral concealed accessory pathway. When antiarrhythmic drugs failed to suppress the arrhythmia, radiofrequency catheter ablation of the accessory pathway was performed without complication.