Although the pathophysiology of Gilles de la Tourette's syndrome is still unknown, effective symptomatic therapies are available. Antipsychotic drugs are the most effective agents for suppressing motor and vocal tics. Haloperidol is the most widely used drug, but pimozide - a closely related drug - is our drug of first choice. Other groups prefer clonidine as the initial treatment. We found a good clinical effect in 81% of patients treated with either pimozide alone or in combination with tetrabenazine. Clonidine or sulpiride have also been used in combination with pimozide with beneficial effect in some patients.In patients with associated behavioural disturbances, we use serotonin reuptake inhibitors, most often in combination with pimozide. Alternatively, clonidine or methylphenidate can be combined with pimozide. In patients who fail to respond to treatment, several other agents with different mechanisms of action can be tried. By combining 2 or 3 drugs which have different sites of action, a more lasting effect can be obtained with lower doses of each drug than with any of the drugs alone. The use of lower dosages is an advantage in long term treatment.