Noninvasive vascular laboratory evaluations were performed on 163 patients who presented with asymptomatic carotid bruits. Of these, 57 patients were identified as having a solely transmitted murmur. The remaining 106 patients had carotid disease. Based on hemodynamic criteria, 77 patients had compensated disease and 29 had uncompensated disease. These patients were followed for from 1 to 56 months (mean 31). Patients in the uncompensated group developed symptoms attributable to the extracranial territory at a higher rate than did patients in the compensated group, with differences continuing for 36 months. At 18 months the accumulated symptom rate for the uncompensated group (24.0%) was over twice that for the compensated group (11.4%). Patients in the uncompensated group also had a higher mortality rate. Differences occurred after 12 months and continued through 36 months. Of the 23 patients who died, 19 (82%) died due to cardiac disease, two due to cerebrovascular accidents, and two due to neoplastic disease. In view of the results of this study, a careful examination of patients with asymptomatic cervical bruits is warranted. This evaluation should take the form of a noninvasive vascular laboratory evaluation, which can help determine the proper course of patient management by measuring functional deficit and estimating anatomic severity.