SURGICAL OPTIONS FOR Parkinson's disease (PD) are rapidly expanding and include ablative procedures, deep brain stimulation, and cell transplantation. The target nuclei for ablative surgery and deep brain stimulation are the motor thalamus, the globus pallidus, and the subthalamic nucleus. Multiple factors have led to the resurgence of interest in the surgical treatment of PD: 1) recognition that long-term medical therapy for PD is often unsatisfactory, with patients eventually suffering from drug-induced dyskinesias, motor fluctuations, and variable responses to medication; 2) greater understanding of the pathophysiology of PD, providing a better scientific rationale for some previously developed procedures and suggesting new targets; and 3) use of improved techniques, such as computed tomography- and magnetic resonance imaging-guided stereotaxy and single-unit microelectrode recording, making surgical intervention in the basal ganglia more precise. We review the present status of ablative surgery and deep brain stimulation for PD, including theoretical aspects, surgical techniques, and clinical results.