The objective of this study was to trigger the formation of rat abdominal aortic aneurysm by applying calcium chloride periarterially and then to detect the degree of prevention of aneurysm occurrence by oral introduction of indomethacin in some of the rats. Thirty-one rats were divided into three groups. The infrarenal aorta above the iliac bifurcation of rats was treated with sodium chloride in group 1 (control, n = 7), calcium chloride in group 2 (n = 12), and calcium chloride-indomethacin in group 3 (n = 12) periarterially. The rats of each group were randomly selected at the end of the first, second, and third weeks postoperatively; and vessel diameters of abdominal aortas were measured by digital photography using a micrometer. Aneurysmal development was not observed in any of the rats in the control group. None of the comparisons was statistically significant (p > 0.05). Aneurysmal development was observed in all of the rats in the calcium chloride group. Results from the first, second, and third weeks postoperatively were statistically significant (p < 0.05). A middle aneurysmal development was observed in all rats in the calcium chloride-indomethacin group. Only results from the second and third weeks postoperatively were statistically significant (p < 0.05). Measurements in groups 2 and 3 were statistically significant when compared to group 1 (p < 0.001). However, the mean increase in the indomethacin-treated group (group 3) was only 26.1%. The macroscopic appearance of the control group and an aneurysm induced by calcium-chloride application are shown.