Mitral annulus calcification may directly cause cerebrovascular accidents by serving as a source of calcific or thrombotic emboli. This hypothesis has been supported by recent reports of mobile components associated with mitral annulus calcification detected by echocardiography. Cardiovascular calcifications, including mitral annulus calcification, are common in end-stage renal disease and may develop and progress over a short period of time. We report two patients with mobile components associated with mitral annulus calcification and end-stage renal disease. Serial echocardiography documented that the mitral annulus calcification in these two patients had developed rapidly. Follow-up echocardiography in one patient demonstrated resolution of the mobile elements.