Objective tinnitus is a bothersome and disturbing symptom for the patient and a perplexing-problem for the physician. Tinnitus that is rhythmic and synchronous with the patient's heart beat is rare and may be the only symptom of life-threatening and treatable disease. The diagnosis and treatment of many arteriovenous fistulae are now possible with risks that are less than the potential complications of the untreated lesion. Careful historical data, physical examination with auscultation and X-rays are important ; however, the definitive diagnosis rests upon good selective arteriograms. The use of a catheter with a balloon during the obstruction of the shunt appears to be a worthwhile diagnostic and therapeutic method.