Oral-facial dyskinesia is not uncommonly encountered as side-effect of chronic phenothiazine treatment or levodopa therapy, is less commonly seen during the course of known hereditary or acquired basal ganglia diseases, and is rarely seen under other circumstances. Two cases of spontaneous oral-facial dyskinesia are described. The pathology and pathophysiology of this type of involuntary movement disorder are unknown, and the prognosis is uncertain. No effective treatment is yet available.