PURPOSE: To evaluate the association between carotid and coronary atherosclerosis and other conditions related to the prevalence of carotid disease. METHODS: Duplex scanning of carotid arteries was performed in 130 patients (70 males and 60 females), with ages between 26 and 89 years-old. Accordingly to the presence of ischemic heart disease, they were divided in 3 groups: I) with proved ischemic heart disease; II) with low probability of disease and III) with high probability of disease. The carotid atherosclerosis was classified as absent (normal result), mild (obstruction below 30%), moderate (30-49%), moderate/severe (50-74%), severe (> 75%), and total occlusion (abnormal results) by Doppler criteria. RESULTS: Normal carotids were found in 44 (33.9%), mild atherosclerosis in 68 (52.3%), moderate in 7 (5.4%), moderate/severe in 5 (3.8%), severe in 5 (3.8%) and total occlusion in 1 (0.8%) of the 130 patients. The prevalence of the disease increased with age (31.2% in patients until 54 years-old, 66.3% in those with age between 55 and 76 years-old, and 88% in those with 77 years-old or more), and it was higher in males than females (75.7% x 55%). All the differences were of statistical significance. In the 48 patients of group I, 41 (85.4%) had abnormal carotids (26 mild, 6 moderate, 3 moderate/severe, 5 severe, and 1 total), whereas in the 64 patients of group II, 27 (42.2%) were abnormals (24 mild, 1 moderate, and 2 moderate/severe), significant difference with p < 0.001. This significant difference persisted when the groups II and III were joined, and 45 (54.9%) of 82 patients had abnormal carotids. All the patients with severe obstruction of carotid arteries (6 patients) had severe coronary obstruction. CONCLUSION: The prevalence of carotid atherosclerosis was high, in 66.2% of the patients. It increased with age, and it was higher in males than females. There was statistically significant association between carotid and coronary atherosclerosis, and the presence of severe carotid obstruction was related to presence of severe coronary obstruction.