One hundred forty-nine consecutive patients who had peripheral arterial disease (PAD) with clinically audible asymptomatic bruits were studied. Sixty-two of these patients were age- and sex-matched with 62 PAD patients in whom no bruits were detected. The PAD was demonstrated by angiography or by the 1-minute exercise test. Clinical assessment was performed every 6 months and oculoplethysmography and carotid phonoangiography (OPG/CPA) were performed every year. Angiography and reconstructive surgery were performed only if symptoms of transient ischemic attack (TIA) or stroke occurred. Life-table analysis revealed that over a 5.5-year follow-up, 32% of 211 PAD patients were expected to die. In the control study 45% of bruit patients and 32% of control patients were expected to die (no significant difference). Myocardial infarction accounted for 59% of deaths in the bruit group compared with 28% in the control group (no significant difference). TIA occurred more commonly in the bruit group (26.5%) than in the controls (6%) (p less than 0.02). However, stroke without warning occurred in 9% of bruit patients compared with 8% of controls (no significant difference). It is concluded that for asymptomatic carotid bruit it is safe to wait for the onset of symptoms before angiography and corrective reconstructive surgery.