BACKGROUND: Hemolysis is a well-recognized consequence of microsecond pulsed-field ablation (PFA); however, its occurrence with nanosecond PFA has not been determined. OBJECTIVES: The aim of this study was to compare hemolysis profiles across different PFA systems. METHODS: Consecutive patients with atrial fibrillation undergoing first-time PFA with Pentaspline (FARAWAVE; Boston Scientific), Lattice tip (Sphere-9; Medtronic), or Nano PFA 360 (CellFX; Pulse Bioscience) catheters were included in this prospective analysis. Hemolysis was assessed by haptoglobin (Hp), lactate dehydrogenase, and bilirubin measured before ablation (T1) and 24 hours after the procedure (T2). Hemolysis was defined as a >10 mg/dL decrease in Hp between T1 and T2. Significant hemolysis was defined as Hp ≤ 25 mg/dL. RESULTS: A total of 94 (67% male, mean age 58.9 ± 11.68) patients were included. No statistically significant differences in the baseline and procedural characteristics were found among the 3 systems. The catheters used were Nano PFA 360, Pentaspline, and Lattice tip in 30 (32%), 34 (36%), and 30 patients (32%), respectively. Hemolysis occurred in 88 (93.6%) patients. Significant hemolysis was observed in 21 (70%) Nano PFA 360, 27 (79.4%) Pentaspline, and 7 (23%) Lattice tip cases (P < 0.001). Multivariable analysis showed that the Nano PFA 360 and Pentaspline were associated with a similarly high risk of significant hemolysis compared with Lattice tip (P < 0.001). No statistically significant difference was observed between Nano PFA 360 and Pentaspline catheters. CONCLUSIONS: Hemolysis commonly occurs across PFA procedures, irrespective of pulse duration, and is greater with single-shot than focal systems.