ABSTRACT Introduction Data regarding safety and long‐term outcome of very high‐power‐short duration (vHPSD) ablation in adult congenital heart disease (ACHD) patients with paroxysmal or persistent atrial fibrillation (AF) are lacking. Methods Retrospective observational single‐center study. The data of 66 consecutive ACHD patients (mean age 60 ± 12.8 years, 46% male) with mild (69.7%), moderate (22.7%), or complex (7.6%) congenital heart disease (CHD) who underwent ablation for paroxysmal (40.9%) or persistent AF (59.1%) were analyzed. Circumferential PVI was performed in all patients and additional substrate ablation in 79,4% of persistent AF patients using irrigated RF energy with vHPSD settings of 70 W/5–7 s or 60 W/7–10 s. Results Mean procedure time was 123.6 ± 42 min with a mean RF time of 18.19 ± 10 min. No technique related adverse events occurred. Vascular access complications were detected in seven patients (10.6%) requiring intervention in four patients (6%). A median follow‐up time of 491 days (IQR: 194–1054 days). Freedom from any atrial arrhythmia off antiarrhythmic drugs (AAD) at 1 year was present in 58% of patients (77.8% with paroxysmal AF, 43.6% with persistent AF). Conclusion vHPSD for ablation of paroxysmal or persistent AF in ACHD patients is safe and effective. Regardless of CHD complexity, no vHPSD ablation modality related complications occurred. Long‐term outcome for paroxysmal AF after one ablation was excellent whereas results for persistent AF were limited.