We examined the extent of extracranial carotid atherosclerosis as evaluated by a B-mode ultrasound score in four groups of hospitalized patients: hospital controls free of both cerebrovascular symptoms and coronary atherosclerosis (HC, n = 245); patients with coronary atherosclerosis but without cerebrovascular symptoms (CAD, n = 382); patients with transient ischemic attacks but asymptomatic for coronary atherosclerosis (TIA, n = 107); and patients having both transient ischemic attacks and symptomatic coronary events (TIA + CAD, n = 39). The unadjusted B-mode scores were lowest for the HC group, intermediate for the CAD group, and highest for the TIA or TIA + CAD groups (no difference between these two groups). However, after adjustment for age (or age and other risk factors), we could find no significant differences among the CAD, TIA, and TIA + CAD groups, while the HC group had significantly lower adjusted scores. These data suggest that 1) accentuated development of carotid atherosclerosis is associated with both TIA and CAD and 2) the apparent differences in extracranial carotid atherosclerosis between coronary and cerebrovascular patients are partly attributable to differences in risk factor profiles (most notably age). The potentially accentuated rate of development of extracranial atherosclerosis in patients with CAD mandates a low threshold for cerebrovascular evaluation in CAD patients.