BACKGROUND: A study in old patients on the incidence of aneurysms in abdominal arteries (AAA) and on the maximum diameter of the aorta below the renal arteries in those patients without arterial dilatation. MATERIAL AND METHODS: The study comprised 411 individuals, 218 women and 153 men with an average age of 74.4 years. Physical examination of the abdomen (EF) and abdominal ultrasonography (US) were done, and the latter was considered the "golden standard" of reference. In relation to the aorta, it was considered as an aneurysm the maximum artery diameter larger than 30 mm and for the iliac arteries, the maximum diameter larger than 15 mm. RESULTS: The US showed the presence of aneurysm in the aortic-iliac territory in nine patients, one woman and eight men, corresponding to a prevalence of 2.1%, 4.1% in men and 0.4% in women. Two such aneurysms were in the iliac arteries (one aneurysm in a common iliac artery) and the other seven in the aorta below the renal arteries. The bearers of iliac aneurysm are men. The prevalence of the AAA was of 1.7% (7/411), 3.1% in men and 0.4% in women. The EF showed suspicion of the presence of aneurysm in 3 of these patients. The other 6 patients had no aneurysm. Considering all the aneurysms of the aortic-iliac territory, the EF had a sensitivity of 33.3%, a specificity of 99% and a positive prediction value of 33.3%. Considering only AAA, the sensitivity of the EF was 42.8%, the specificity 98.5%, and the positive prediction value, 33%. In the 402 patients without arterial aneurysm the maximum diameter of the aorta varied from 11 to 29 mm, with an average value of 16-21 mm. CONCLUSIONS: US is a non-invasive diagnostic procedure that should be used for the old age population.