A 45-year-old woman with an acquired multifocal neurologic syndrome, including chorea, dystonia, cerebellar dysfunction, multiple cranial neuropathies, and pure sensory neuropathy, was found at autopsy to have oat cell carcinoma. Neuropathologic examination revealed several features typically associated with remote effects of malignancy on the nervous system. We believe that this is the first described case of chorea as a remote effect of malignancy.