To establish possible relationships between the structure of carotid plaque and neurologic symptoms, 187 consecutive endarterectomy specimens were studied prospectively. Each specimen was examined for gross and histopathological features. Intraplaque hemorrhage, although found infrequently, was closely correlated with the presence of symptoms. Plaque ulcerations were encountered more often when lesions were symptomatic. Calcifications were more frequently associated with asymptomatic lesions. Consistency of plaque was related to its morphological features (stenosis or ulceration) and symptoms. Soft plaques with predominant atheromatous grumous material and hemorrhage were associated more often with tightly stenotic, ulcerated, and symptomatic lesions. Consistency of atherosclerotic carotid plaques should be assessed and considered as an important element in the therapeutic decision.