Thirty-two patients (26 female, 6 male) with angiographically diagnosed Takayasu arteritis were seen at the Mayo Clinic between 1971 and 1982. Racial composition of this group was 23 North American Caucasians, 4 Mexicans, 3 Orientals, 1 Native American, and 1 patient of Middle Eastern origin. Incidence of the disease in Olmsted County, Minnesota, was 2.6/million/year. Diagnosis was often delayed for long periods of time, with a median delay of 18 months. Patients had both non-vascular symptoms (arthralgias in 56%, fever in 44%, weight loss in 38%) and symptoms of vascular stenosis such as arm claudication (47%) and hypertension due to renal artery stenosis (41%). All patients had either multiple vascular bruits (94%) or absent pulses (50%). Laboratory findings included anemia (44%) and elevations of erythrocyte sedimentation rate (78%). Almost all patients had multiple sites of arterial involvement documented by angiogram with various combinations of stenosis, luminal irregularity and aneurysm formation. Response to corticosteroid treatment was usually very good, with dramatic improvement in non-vascular symptoms and return of pulses in 8 of the 16 patients with absent pulses prior to treatment. Five-year survival rate from time of diagnosis was 94%. Twelve patients underwent surgical procedures involving the carotid arteries (5 cases), subclavian artery (4 cases) and renal arteries (3 cases). Three aneurysms were resected, one had aortic valve replacement for severe aortic regurgitation, and two patients underwent transluminal angioplasty. Pathologic changes were restricted to the media and adventitial layers of the vessel wall and were indistinguishable from those of giant-cell or temporal arteritis. Takayasu arteritis is more common than previously suspected in North America, is not restricted to any one racial group, and is readily treatable with corticosteroids and surgical vascular reconstruction.