• We examined race and sex relative to the unexpected finding of an abdominal aortic aneurysm (AAA) at 1,665 autopsies plus 545 abdominal computed tomographic scans in subjects over the age of 50 years. We compared our demographic data with those of North Carolina and our hospital to determine if the data base was representative. White males had a higher incidence (4.2%) of AAA than any other group of race and sex (1.2% to 1.6%) or combination of groups. Although whites (2.9%) had a higher incidence than blacks (1.5%) and males (3.4%) had a higher incidence than females (1.3%), this can be attributed to the influence of the white male. The demographic data of the group studied were similar to those of our institution's admissions and to the North Carolina population. We conclude that (1) there is an increased incidence of AAA in the white male compared with the white female, black male, and black female in North Carolina; (2) there is no difference in the incidence of AAA in the white female, black male, and black female; (3) race alone may not influence the incidence of AAA as there was no difference between white and black females. (Arch Surg 1985;120:1138-1140)