Unilateral pallidotomy has been accepted as an effective therapeutic option for Parkinson’s disease (PD). We herein report a PD patient with wearing-off and dyskinesia who underwent left globus pallidus internus (GPi) pallidotomy using magnetic resonance imaging-guided focused ultrasound (MRgFUS). Her skull density ratio (SDR) was too low to perform MRgFUS procedure; however, it improved with bisphosphonate. Right-sided wrist rigidity, finger movement, and resting tremor improved immediately following the ultrasound energy delivery. Wearing-off improved and dyskinesia abolished after the procedure. No severe adverse events were observed. MRgFUS is a minimally invasive treatment; however, further investigations concerning not only technical problems such as SDR but also long-term efficacy and safety of this new treatment for PD patients should be necessary.