Traditional neuropathologic methods have provided only limited insight into the central nervous system abnormalities underlying Tourette syndrome. In the past 20 years, investigators have turned increasingly to in vivo neuroimaging approaches to localize, quantify, and characterize neuroanatomic, functional, and neurochemical distinctions in living subjects with Tourette syndrome. Research methods have included aggregate measures of cerebral energy metabolism, assessments of cerebral structure and size, and highly specific assessments of neurochemical markers of select neurons and synapses. Although the available data have important limitations, an encouraging convergence of findings implicates abnormal function in the Tourette syndrome striatum and in associated limbic and frontal cortical systems.