A 21-year-old woman with a history of systemic lupus erythematosus (SLE) was admitted with dyspnea on exertion for a year. A transesophageal echocardiogram showed dilated aortic root with intimal thickening. A positron emission tomography/computed tomography demonstrated increase in glucose hypermetabolic along the walls of the aortic valve, ascending aorta, aortic arch, and aorta, vasculitis was observed. She underwent the Bentall operation due to inflammation at sinus of right coronary cusp. She started high dose glucocorticoid after the operation. Currently she is able to sustain with low dose steroid after gradually tapered. Her symptoms were disappeared, and inflammatory markers decreased to within the normal range. Aortitis and aortic aneurysms are an uncommon manifestation of SLE. Furthermore, almost of lupus patients with medium and large vessel vasculitis are not biopsied or studied histologically. We present first case in Korea that was a 21-year-old woman who diagnosed with lupus aortitis by pathology after aortic valve replacement operation.