A murine abdominal aortic aneurysm model was developed by applying calcium chloride periarterially. A 13.6 mEq/10 ml calcium chloride solution was applied to the abdominal aorta of nine mice. Three mice were randomly selected at the end of the first, second, and third weeks postoperatively, and their vessel diameters were measured. The vessel diameter at the end of the first week postoperatively was 0.39 ± 0.03 mm (mean ± SD) pretreatment and 0.41 ± 0.03 mm posttreatment (5.3% increase, P > 0.05). The vessel diameter at the end of the second week postoperatively was 0.48 ± 0.03 mm pretreatment and 0.78 ± 0.20 mm posttreatment (64% increase, P < 0.05). The vessel diameter at the end of the third week postoperatively was 0.57 ± 0.14 mm pretreatment and 1.16 ± 0.43 mm posttreatment (110% increase, P < 0.05). Nine other murine abdominal aortas were treated with sodium chloride, and their vessel diameters were measured in similar 7-day intervals. No measurements in this group were statistically significant when comparing pretreatment to posttreatment vessel diameters. A larger number of inflammatory infiltrates was observed in the intima and media layers of calcium-chloride-treated mice. Underlying mechanisms for this model include disrupting the elastic network within the media by calcium precipitations and activating the inflammatory response. We conclude that periarterial application of calcium chloride is a convenient and reliable model for creating abdominal aortic aneurysms in mice.