A 25-year-old man with a history of Tourette's syndrome presented for treatment of OCD symptoms. Fluvoxamine worsened tics, led to coprolalia, and did not help the OCD. The addition of pimozide dramatically reduced both OCD and Tourette's symptoms. Double-blind sequential discontinuation of fluvoxamine and pimozide confirmed that pimozide alone reduced only tics and the combination of fluvoxamine and pimozide was required for the improvement in OCD. Tics may reflect a subtype of OCD. Some OCD patients unresponsive to a 5-HT reuptake inhibitor alone may benefit from the addition of a dopamine antagonist.