The aim of this study was to determine the maximal aneurysm diameter (MAD), the total aneurysm volume (TAV), the intra-aneurysm vascular channel (IAVC), and total thrombus volume (TTV) and compare changes in those parameters during a 12-month time period. In addition, these parameters for three different endovascular grafts were compared. A retrospective review of 42 patients who had undergone endovascular aneurysm repair (EVAR) between July 1999 and March 2001, and without evidence of an endoleak or migration, was performed. The minimum follow-up in this group was 12 months. The three grafts deployed were Dacron-stainless steel bifurcated grafts with suprarenal fixation [Zenith; Cook, Inc. (n = 14)], Dacron stainless steel aorto uni-iliac grafts with suprarenal fixation [custom-made (n = 10)], and externally supported Dacron nitinol bifurcated grafts [AneuRx; Medtronic, Inc. (n = 18)]. Volumetric measurements were obtained from CT images performed preoperatively, at 1 month and 12 months thereafter, using a 3-D Magicview 1000 workstation (Siemens, Inc.). Regardless of the type of endograft, a significant change in MAD and TAV (P = 0.008), IAVC (P = 0.031), and TTV (P = 0.001) was observed over the 12-month postoperative period. Both maximum diameter and total aneurysm volume appear to reflect accurately successful aneurysm exclusion. We conclude that both two-dimensional, maximal aneurysm diameter and three-dimensional, total aneurysm volume accurately reflect changes in morphology after endovascular aneurysm repair.