Takayasu's arteritis is a chronic vasculitis, the etiology of which is still unknown. This condition involves primarily the aorta, its main branches, and the coronary and pulmonary arteries. One epidemiologic characteristic of this morbid condition is that almost all patients come from Asian and South American countries, which has led to searches in the role of genetic factors in its pathogenesis. International surveys on HLA analysis have focused on HLA-B52 and B39 disequilibrium with this morbid condition. These comparative studies have made clear the different characteristic clinical manifestations among Asian and South American countries, which will prompt further studies in relation to genetic factors in the future.