BACKGROUND: Off-label under- and overdosing of direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) is not uncommon in real-world practice. OBJECTIVE: This study aimed to identify efficacy and safety of off-label DOACs dose after AF ablation. METHODS: The RYOUMA registry was a prospective multicenter study of Japanese patients who underwent AF ablation between 2017 and 2018. DOAC prescriptions were categorized into on-label standard dose, on-label reduced dose, off-label underdose, and off-label overdose. RESULTS: The proportion of off-label doses among patients after AF ablation varied depending on the type of DOAC, ranging from 13.5% to 34.9%. Of 2821 patients, 366 (13.0%) were prescribed an off-label underdose and exhibited significantly higher CHADS CONCLUSIONS: In patients after AF ablation, off-label DOAC overdose was infrequent, but significantly associated with higher incidence of major bleeding during the remote period after AF ablation. TRIAL REGISTRATION: The study was registered as UMIN000026092 (University Hospital Medical Information Network-Clinical Trial Registry).