High-frequency deep brain stimulation (DBS) of the thalamus or basal ganglia represents an effective clinical technique for the treatment of several medically refractory movement disorders, including Parkinson's disease. However, understanding of the mechanisms of action of DBS remains elusive. The goal of this review is to address our understanding of the effects of high-frequency stimulation within the central nervous system based on results from functional imaging, neural recording, and neural modeling experiments. Using these results, we address the main hypotheses on the mechanisms of action of DBS and conclude that stimulation-induced desynchronization of network oscillations represents the hypothesis that best explains the presently available data.