This report documents the case of a male in his sixties who developed multiple lymph node metastases after receiving external beam radiation therapy and androgen deprivation therapy for locally advanced prostate cancer. Agglomerated pelvic lymph node metastases caused lower extremity lymphedema, however the patient was administered systemic chemotherapy with docetaxel. Because surrounding normal tissue was already irradiated by the prior therapy, radiation against pelvic lymph nodes by LINAC was in danger of exceeding tolerance dose. Therefore, the patient received stereotactic radiosurgery by cyberknife that has a high degree of accuracy in target identification and localization for pelvic lymph node metastases. The lower extremity lymphedema was declined and his activity of daily living was recovered without obvious side effects. Here we report the case of successfully controlled lymphedema by palliative cyberknife therapy.