Tourette's disorder is a complex, multifaceted condition of neurological origin with psychiatric symptomatology characterized by multiple motor and vocal tics. It begins during childhood and has a waxing and waning course. Coexisting obsessive-compulsive symptoms, attentional problems, and other behavioral features are common. Pathophysiology involves dysfunction in basal ganglia and related corticothalamic circuits. Many patients who present in clinical settings have mild to moderate symptoms and require only education, monitoring, and long-term follow-up. Those with more-severe symptoms require treatment, typically including both pharmacotherapy and nonmedication approaches. In addition to traditional neuroleptic treatment, a variety of agents such as clonidine, serotonin-reuptake inhibitors, and tricyclic antidepressants can be used. Further investigation is needed in a variety of areas, including longitudinal follow-up studies of children, adolescents, and adults with Tourette's disorder; systematic investigation of psychiatric comorbidity and the heterogeneity of the disorder; clarification of the phenomenological similarities and differences between Tourette's disorder and obsessive-compulsive disorder; and neuroimaging and neuropsychological studies of Tourette's disorder and related problems.