A Series presenting the results of activities sponsored by the NATO Science Committee, which aims at the dissemination of advanced scientific and technological knowledge, with a view to strengthening links between scientific communities. The Series is published by an international board of publishers in conjunction with the 385) 91, boulevard de I'Hopital 75634 PARIS cedex 13 (France) ABSTRACf. The physiological mechanisms underlying oral communication are of primary interest.Investigations concerning the motor acts of speech are limited to what can be inferred from observation of the peripheral mechanisms of speech production. The neuromuscular events of speech movement patterning are described. In addition, speech movement coordination involves substantial adjustments among the multiple muscles of the various articulatory organs. The cerebellum is an important regulatory center for the control of motor activity. It provides smoothness to the contraction of synergist and antagonist muscles. It uses sensory information to predict, judge and correct the motor act. Damage to a structure with this capability would be expected to have consequences on speech production . The role of the cerebellum in speech control is examined by assessing the effects of cerebellar lesions on speech through a short review of literature.