AIMS: Pulsed field ablation (PFA) is a ablation modality that is increasingly used for pulmonary vein isolation (PVI) in atrial fibrillation (AF) patients. This study assessed the safety and effectiveness of a balloon-based PFA system at 6 months after treatment. METHODS AND RESULTS: This study is a prospective, single-center, premarket study. A total of 56 patients with drug-refractory paroxysmal atrial fibrillation (PAF) were enrolled between November 2024 and September 2025 and underwent PVI with a balloon-based PFA system. The study endpoints were the rate of primary serious adverse events, acute procedural effectiveness and 6-month freedom from recurrence. Acute effectiveness was achieved in 100% (231/231) of the treated PVs (100% of patients, 56/56), with 33 ± 5.5 PFA applications/patient. The procedure, fluoroscopy, and transpired ablation times were 89.0 ± 30.7, 24.2 ± 8.3, and 20.0 ± 12.0 min, respectively. One (1.8%; 1/56) primary serious adverse event occurred: one patient developed intraoperative gastrointestinal bleeding due to TEE-induced mechanical injury. One patient developed a cerebral infarction on postoperative Day 28. The rate of freedom from documented atrial arrhythmias was 92.9% through 6 months after the index procedure. CONCLUSION: The primary results of this study demonstrate the safety and effectiveness of the balloon-based PFA system for performing PVI in patients with PAF.