Background The percutaneous epicardial catheter ablation (PECA) by subxiphoid approach is known to be feasible and is to be considered in epicardial origin of ventricular tachycardia (VT). We report the early experiences and outcomes of PECA in patients with tachyarrhythmias (VT or atrial fibrillation: AF) refractory to endocardial approach. Methods and Results We applied PECA in 8 patients (8 males, age 47.1짹8.8 years old) when they were 1) difficult to map, 2) at high risk of complications, or 3) not amenable to effective RF energy delivery by endocardial approach. Pericardium was punctured by 20G Tuohy needle and 0.032��� guide-wire was inserted in the pericardial space followed by 8Fr aluminium shaft sheath or multipurpose long sheath. We used RF generator setting 50W, 60째C for 5mm tip conventional catheter, and 30W, 42째C for internal irrigation tip catheter. Results: 1. The underlying disease were 2 ischemic VTs (right ventricular (RV) basal anterior wall, LV apical anterolateral wall), 2 non-ischemic VTs (left ventricular (LV) basal anterolateral wall, RV basal posteroseptum), a LV non-compaction (apicoanterolateral wall), an idiopathic repetitive monomorphic VT (basal posteroseptum), and 2 recurred persistent AF after RF ablation (high risk of pulmonary vein stenosis). 2. In patients with VT (n=6), the discrete pre-systolic or mid-diatolic potential was observed in 4 patients and polarity reversal between distal and proximal pole of mapping catheter in all patients at the epicardial target site, respectively. 3. In patients with AF, PECA was performed at the junction between left atrial appendage and left pulmonary trunkus and ligament of Marshall area. 4. We achieved successful ablation in all patients, and hemopericardium occurred in 1 patient who was punctured by needle with too shallow angle during PECA. During 11.0짹9.6 months of follow-up, a patient with persistent AF and a patient with non-ischemic VT recurred. Conclusion In our early experience, PECA could be safely applied in patients with arrhythmias which were unsuccessful to map and ablate endocardially. It is noteworthy that puncture technique and angle are important to avoid epicardial injury during PECA.