Aortic regurgitation (AR) is not a rare complication of Takayasu's disease and is now considered as an important risk factor related to mortality. Aortic-valve replacement surgery is the only curative treatment, but cardiac function and mortality after surgery have not been reported, so a follow-up study in 10 patients with Takayasu's disease complicated by AR was performed. Six patients underwent aortic-valve replacement surgery and all had improvement of the ejection fraction and a decrease in the size of the left ventricle size on echocardiography. Three of the 6 cases had a remote cardiovascular event. Detailed pathological examination carried out in one case of the aortic valve and aortic specimen from surgery showed only lymphoid cell infiltration around the capillary in the ascending aorta, and no other inflammatory change. Inflammation was well controlled at surgery by pre-operative steroid therapy, so early and aggressive aortic-valve replacement surgery with peri-operative immunosuppressive therapy should be considered for patients with Takayasu's disease. (Circ J 2002; 66: 564 - 566)