['There is scanty information concerning multiple aortic aneurysms. Thus, we verified if clinical or pathological characteristics are different in patients with multiple (two or more) aortic aneurysms in comparison with those with only one.', "We selected at the necropsy files of the Heart Institute, São Paulo University School of Medicine, the last 100 cases with aortic aneurysms, comparing between the two groups: sex, age, presence of systemic arterial hypertension, diabetes, dyslipedemia, history of smoking habit, cause of the aneurysm, cause of death, and if the diagnosis was reached during life. Age was analysed by Mann-Whitney test, and the other variables by chi-square or Fisher's exact test.", 'Multiple aneurysms corresponded to 14% of cases. The proportion of women among patients with multiple aneurysms was higher than among those with single aneurysm (64.3% versus 20.9%, P<.01), even if only cases with atherosclerosis were taken into consideration (women among multiple-6/10, 60.0%; among single-14/70, 20.0%; P=.01). Smoking was less reported in cases with multiple (4/14, 28.6%) than with single aneurysm (53/86, 61.6%; P=.04); considering cases with atherosclerosis, such difference decreases (40.0% of multiple versus 68.6% of single, P=.09).'] Are male gender and smoking related to single , but not to multiple , human aortic aneurysms?