Repair of completely lost mitral leaflet segments is technically challenging, particularly via minimally invasive cardiac surgery. We report a case of iatrogenic mitral regurgitation following catheter ablation, successfully treated with minimally invasive mitral valve repair using a seamless patch technique. A 55-year-old man developed severe mitral regurgitation and moderate tricuspid regurgitation after repeated ablations for ventricular tachycardia. Intraoperatively, the P1 leaflet and chordae were completely absent with subannular scarring. Seamless patch reconstruction was performed using glutaraldehyde-treated autologous pericardium recreating a dome-shaped P1 segment, combined with ring annuloplasty. Postoperative recovery was uneventful with normal valve function at 2-year follow-up.