Background Some of outflow tract ventricular tachycardias (VTs) are known to be successfully ablated from the aortic cusp (AC). However, the electrophysiologic characteristics of supraventricular tachyarrhythmia (SVT) of AC origin have not yet been reported. Methods and Results From 2005 to 2008, we experienced 30 patients (43.7짹15.6 years old, Female 51.7%) with AC arrhythmias (6 atrial tachycardias (AT), 2 atrioventricular reciprocating tachycardia (AVRT), and 22 VTs). We reviewed the prevalence, the location of successful ablation, and electrophysiologic characteristics of AT-SVT. Results: 1. Among 78 patients with AT (41.7짹17.6 years old, 49% female) who underwent radiofrequency catheter ablation, 8 patients had AT of para-Hisian septal origin and 6 patients (7.7%, 44.2짹27.6 years old, 83.4% female) underwent successful ablation from non-coronary cusp (NCC) using a retrograde aortic approach. 2. The mean number of RF delivery at NCC was 1.7짹1.2 and the time taken for AT to be terminated was 7.0짹1.4 sec. 3. Among 316 patients with AVRT (37.5짹15.2 years old, 68% male) who underwent RFCA, 22 patients had para-Hisian bypass tract (BT) and 2 patient (0.6%, 42.5짹16.3 years old, 100% male) with left mid-septal BT was successfully ablated at NCC in close proximity to the area recording His potential. 4. RF delivery (20W, 55째C) was performed 1.5짹0.7 times while watching 1:1 AV ratio, and the BT was ablated in 12.8짹7.3 sec without a AV block or delay. 5. There was no complication after RFCA, and all patients, except 1 patient who had 3 different AT foci (NCC, coronary sinus ostium, and low crista), have been arrhythmia free during 11.6짹3.4 months of follow-up. Conclusion Catheter ablation within the NCC is a safe and effective procedure to eliminate focal AT arising from the peri-AV nodal region or AVRT using para-Hisian BT.