To assess ferromagnetic properties of intracranial aneurysm clips reported to be nonferromagnetic, 1,765 Yasargil, 11 Sugita, and 15 Perneczky aneurysm clips were studied for rotation or translation on plate glass in a 1.5-T MR imager. Sixty-three clips (52 Yasargil, 11 Perneczky) weakly reoriented along the static magnetic resonance (MR) field. These results confirm the need for standardized testing for ferromagnetic properties for implantable metallic devices.