A 71-year-old woman with a 25-year history of levodopa (LD)-responsive Parkinson's disease (PD) developed on-off motor fluctuation and severe peak dose dyskinesia. She underwent deep brain stimulation of the subthalamic nucleus (STN-DBS). STN-DBS induced attenuation of her cardinal PD symptoms and marked improvement of dyskinesia without reduction of LD dosage perioperatively. STN-DBS thus markedly attenuated the cardinal symptoms of PD. LD-induced dyskinesia can also be controlled via reduction of LD dosage as an indirect effect of STN-DBS. The present case provides evidence of the direct antidyskinetic effect of STN-DBS, and suggests that LD-induced dyskinesia can be inhibited by stimulation in the area above the STN.