The patient was a 15-year-old girl with suspected Takayasu arteritis. Magnetic resonance (MR) imaging, using the fast low angle shot (FLASH) technique, revealed aneurysmal dilation of the aortic root and irregular thickening of the aortic wall. Three-dimensional (3-D) contrast-enhanced MR angiography successfully demonstrated narrowing of the left carotid and left subclavian arteries. In addition, 2-dimensional (2-D) FLASH MR imaging clearly visualized narrowing of two right renal arteries and the left renal artery. These were angiographically evident. Thus, MR imaging is particularly useful for early detection of subtle arteritic changes and involvement of stenotic lesions in branch vessels in the early phase of Takayasu arteritis.