Vestibular impairments have not been routinely identified in patients with multiple sclerosis (MS), because of the confounding effects of deficits in other neural systems. In this study, 35 patients with MS were evaluated by means of a systematic alteration of the sensory environment (dynamic posturography) in order to identify those patients who became unstable when vestibular inputs were needed to maintain stance. Subjects were assigned to either a high-function (HF) or a low-function (LF) group on the basis of a functional status assessment score obtained prior to the posturography test. For the HF group, 30% (7/23) had abnormal posturography scores. Of those subjects, 3 had a vestibular dysfunction pattern or a somatosensory-vestibular impairment. In contrast, 58% of the LF group (7/12) had abnormal posturography scores. Nearly all of these LF patients (6/7) had a vestibular dysfunction pattern or a combined visual-vestibular or somatosensory-vestibular impairment. Posturography might serve as one method to evaluate the functional consequences of a vestibular deficit in patients with MS.