An Uhthoff-like phenomenon was recently observed in a patient with clinically definite MS who experienced transient dysphonia brought on by exertion and relieved by cooling. The patient's dysphonia was felt to be related to intermittent temperature-dependent conduction block associated with a demyelinating plaque in the region of the left nucleus ambiguus. We have termed the patient's intermittent dysphonia 'laryngeal Uhthoff's phenomenon'.