Aortic arch aneurysm (AAA) is a rare involvement in Behçet disease (BD). It is often life-threatening, yet few reports related to the treatment of AAA have been published. We herein report a 27-year-old woman with AAA caused by vascular BD. She was initially treated with prednisolone 1 mg/kg/d. However, the inflammation had not subsided after three weeks, so infliximab (IFX) was added for relief. After IFX administration, the C-reactive protein level normalized, and computed tomography at three months after therapeutic intervention revealed that the aneurysm had disappeared. This case suggests that early induction of IFX might be effective for aortic aneurysm in BD.