Purpose: Bypass grafts that originate from the descending thoracic aorta to the iliac or femoral arteries are well described but are not commonly used as primary procedures, and the long-term results remain unknown. A 15-year experience with 50 descending thoracic aorta to iliofemoral artery bypass grafts for aortoiliac occlusive disease is the basis of this report. Methods: From January 1983 to December 1997, patients who underwent bypass grafting procedures from the descending thoracic aorta to the iliac or femoral arteries were identified. Surgical indications, morbidity and mortality rates, primary and secondary patency rates, limb salvage rates, and survival rates were determined. Results: Fifty descending thoracic aorta to iliofemoral artery bypass grafting procedures were performed - 24 (48%) for severe claudication, 22 (44%) for rest pain, and 4 (8%) for ischemic ulceration. A primary procedure was performed in 31 patients (62%) for complete occlusion (21 patients) and severe atherosclerotic disease (10 patients) of the infrarenal aorta. The indications for 19 secondary revascularizations (38%) were prior aortic or extra-anatomic graft failure in 17 cases and aortic graft infection in 2 cases. The follow-up periods ranged from 1 to 150 months (mean, 39 months). The cumulative life-table 5-year primary patency, secondary patency, limb salvage, and survival rates were 79%, 84%, 93%, and 67%, respectively. An improved patency trend was observed for patients who underwent operation for severe claudication as compared with limb-threatening ischemia (92% and 69%; P = .07). However, there was no difference between primary and secondary operations in primary patency rates (81% and 79%; P = NS) or survival rates (72% and 62%; P = NS). Conclusion: Descending thoracic aorta to iliofemoral artery bypass grafting has excellent overall long-term results. These results support its more liberal use for primary revascularization, especially for patients with severe atherosclerotic disease or complete occlusion of the infrarenal aorta.