✓ The authors present the case of a 49-year-old woman with disabling bilateral upper-extremity cerebellar tremor that resolved unexpectedly after placement of an intrathecal baclofen pump for lower-extremity spasticity. The tremor amplitude decreased nearly linearly with increasing intrathecal baclofen dosage, and disappeared completely at a dose of 250 µg/day. In this report the authors demonstrate the role of the γ-aminobutyric acidergic system in the pathogenesis of cerebellar tremor, and these findings may lead to a new treatment modality for patients disabled by this manifestation of their disease.