In the postoperative treatment of ruptured abdominal aortic aneurysm surgery, the relationship between intra-abdominal pressure (IAP) and the clinical course is not been clearly understood. From April 2000 to January 2003, we treated 109 cases of abdominal aortic aneurysm surgery (non-rupture 71 cases, rupture 38 cases) and measured intra-abdominal pressure in 30 of the ruptured cases which we analyzed in this study. The patients were divided into 2 groups. The H-group included 12 patients with maximum IAP equal to or higher than 20mmHg, and the L-group included 18 patients with a maximum IAP less than 20mmHg. Clinical characteristics were compared between the 2 groups. The mean age was 79.3±7.6yr in the H-group and 70.7±10.1yr in the L-group (p=0.019). Preoperative shock was diagnosed in 83.3% of the H-group patients, and 61.1% of the L-group patients the (p=0.26). Postoperative maximum values of intra-abdominal pressure were 22.3±2.0mmHg in the H-group, and 15.4±2.4mmHg in the L-group. Duration of intubation was 87.7±110.0h in the H-group, and 25.1±29.2h in the L-group (p=0.04). Food intake was started 14.4±11.2d after surgery in the H-group, and 8.5±4.8d after surgery in the L-group (p=0.094). The length of ICU stay was 6.7±6.5d in the H-group, and 2.9±2.1d in the L-group (p=0.033). Length of hospital stay after surgery was 54.1±25.8d in the H-group, and 25.2±6.8d in the L-group (p=0.001). Complications occurred in 8 cases out of 11 surviving cases (73%) in the H-group, and in 3 cases out of 17 surviving cases (18%) in the L-group (p=0.0024). Complication in the H-group included acute renal failure, paralytic ileus, respiratory failure, abdominal wall dehiscence, and acute arterial occlusion, and that in the L-group included acute renal failure, upper limb paresis, and lower limb paresis. Monitoring of intra-abdominal pressure was considered beneficial to recognize complication and decide therapeutic strategy after ruptured aortic aneurysm surgery.