We herein report two patients with paroxysmal dyskinesias (PD) as the initial manifestation of multiple sclerosis (MS). PD can occur in clinically definite MS or rarely be the presenting symptom. They are produced by demyelinating lesions at any level in the motor pathway or in the thalamus. MRI disclosed an area of demyelination in the posterior limb of the internal capsule contralateral to the PD in the patients reported herein. PD associated with MS do not adjust completely to the accepted classifications of PD, therefore they should be considered a special category of dyskinesias.