Although a variety of dyskinesias are known to develop during anticonvulsant therapy, carbamazepine-induced tics are rarely recognized. We report three patients with an underlying movement disorder (Huntington's disease, tardive dyskinesia, and Tourette's syndrome) who experienced the onset or exacerbation of tics after the introduction of carbamazepine. These cases confirm the phenomenon of carbamazepine-induced tics and suggest that basal ganglia neuropathology may be an important predisposing factor. The dopaminergic effects of carbamazepine may be responsible for the induction of tics.