Right free wall accessory pathway (RFW-AP) with branched atrial insertions is a rare, under-recognized AP which may be associated with initial ablation failure. To investigate the clinical and electrophysiological characteristics of this AP. From January 2011 to March 2018, 10 patients identified with branched RFW-AP were enrolled and 30 consecutive patients with conventional RFW-APs served as control group. Right atrium (RA) was activation-mapped and three-dimensionally reconstructed during AP-mediated orthodromic tachycardia or right ventricle pacing. Atrial insertions were defined as the earliest breakout sites and their relationship with the tricuspid annulus (TA) were described and analyzed. An average of three separate atrial insertions on the atrial side were documented among these 10 cases (female/male=5/5, mean age of 38.0±13.9 years). All the atrial insertions were away from the TA. The nearest atrial insertions averaged 15.9±3.4 mm away from the TA and the farthest atrial insertions were 22.6±5.7 mm away from the TA. Antegrade and retrograde AP conduction remained unaffected after ablation of the first earliest breakout site, but were eliminated by ablating all insertions after an average of 2.5 (range 2-2.5) remaps, 3 sites of ablation (range 2.5-4.5), 21 (range 15.5-37.8) RF applications, and 659.5 (range 464.3-1144.3) seconds RF ablation duration. After 12-months follow-up, no patients reported AP conduction recovery or recurrent tachycardia. RFW-AP with branched atrial insertions is an atypical AP variant and featured by > one distinct atrial insertions on atrial side. Stepwise ablation rather than single focal ablation is required to eliminate all retrograde conduction. Copyright © 2019. Published by Elsevier Inc.