Supraventricular tachycardia is a documented feature of Marfan syndrome. The safety and efficacy of radiofrequency ablation in this population of patients, however, has not been reported. We report on the successful use of radiofrequency ablation utilizing a trans-septal approach for the treatment of supraventricular tachycardia produced by an accessory muscular atrioventricular connection in a patient with Marfan syndrome.