Among 25 patients with extremity lymphedema who underwent noncontrast ultra-high-frequency ultrasound (UHFUS) for preoperative lymphovenous mapping before lymphaticovenous anastomosis (LVA) surgery, the LVA success rate by lymphovenous pair was 96.7% and by patient was 96.0%. UHFUS exhibited high agreement with surgical measurements for lymphatic channel and vein diameters.