A 53-year-old man with Behçet's disease was admitted to our hospital for investigation of back and lower abdominal pain. Computed tomography (CT) showed a projecting saccular aneurysm below the right renal artery. We placed a stent-graft just below the right renal artery, successfully excluding the abdominal aortic aneurysm (AAA). His C-reactive protein level and white blood cell count remained elevated after stent-grafting. About 5 months later, he was readmitted with recurrent back and lower abdominal pain and CT showed progression of the AAA. Thus, we performed straight grafting using a woven Dacron graft just below the right renal artery. The patient had an uneventful postoperative course. We discuss the controversial issue of treating AAA in patients with Behçet's disease, focusing on the indications and timing of surgery.