Comparative study of Takayasu arteritis in 3 Asian countries (India, Korea and Japan) has revealed some significant differences. In angiographic findings, Japanese patients more frequently have lesions at the aortic arch and/or its branches (99% of 96 cases), while most lesions in Korean (76% of 109 cases) and Indian patients (92% of 50 cases) are at the abdominal aorta. The presence of HLA-Bw52 or B5 is closely associated with Takayasu arteritis in all 3 Asian countries. The complications in 108 Japanese, 101 Korean and 50 Indian patients were also compared. The most frequent complications were aortic regurgitation in Japan and hypertension in the other 2 countries. Death occurred most frequently due to congestive heart failure or sudden death resulting from aortic regurgitation in Japan, but resulting from hypertension in Korea and India.