A 32-week, premature neonate with incessant supraventricular tachycardia and hemodynamic compromise who failed to respond to antenatal and postnatal antiarrhythmic therapy underwent successful radiofrequency catheter ablation (RCA) of a concealed left free-wall accessory pathway when the infant was 4-days-old and weighed only 1,840 grams. At follow-up performed 60 days after the procedure, the infant remained free of any drug, in sinus rhythm, and in normal hemodynamic condition.