Objective : We examined the utility of distal perfusion (DP) in open stent grafting (OSG) for the treatment of thoracic aortic aneurysm. Methods : Fifty patients who underwent OSG were categorized into two groups (the Non-DP group and the DP group) based on the presence or absence of distal perfusion in OSG. There was no statistically significant difference between the two groups with regard to patient characteristics. Results : There was no statistically significant difference between the two groups with regard to operation time, but, cardiopulmonary bypass time (178±22 min vs. 193±18 min ; p <0.01) and aortic cross clamp time (84±23 min vs. 106±19 min ; p<0.01) were significantly longer in the DP group. Lower-body circulatory arrest time (46±11 min vs. 20±5 min ; p<0.001) was significantly longer in the Non-DP group. Postoperative paraplegia and paraparesis occurred in one case each in the Non-DP group, whereas permanent spinal cord ischemia did not occur in the DP group. Postoperative intubation time (72.6±40.1 h vs. 40.1±34.7 h ; p<0.05) was significantly longer in the Non-DP group. There were two in-hospital deaths due to stroke and respiratory failure in the Non-DP group, and one in-hospital death due to respiratory failure in the DP group. The postoperative maximum value of BUN (38.5±15.6 mg/dl vs. 30.8±9.8 mg/dl ; p<0.05) and s-Cr (1.9±1.0 mg/dl vs. 1.3±0.4 mg/dl ; p<0.01) were significantly higher in the Non-DP group. Conclusion : DP in OSG was an effective method for prevention of spinal cord ischemia, and for protection of respiratory and renal function.