Jaw claudication accompanies relatively few disorders, but it may be an important presenting feature that heralds serious underlying disease. In temporal arteritis, for example, jaw claudication rather than the classic finding of unilateral lancinating headache may be the distinguishing symptom. In the case reported here, jaw claudication was a prominent symptom for five months in a black woman. Temporomandibular joint disease can produce pain similar to that of jaw claudication, as can rheumatoid arthritis involving the temporomandibular joint in the elderly. Myasthenia gravis closely mimics jaw claudication, and parotid tumors can produce similar pain. Atherosclerotic narrowing of the external carotid artery proximal to the origins of the facial and maxillary branches is a rare cause of jaw claudication. Recognition of the importance of jaw claudication can lead to early identification of the underlying disease and quick initiation of therapy to avoid serious complications.