In the 77-year-old woman described, atherectomy of a circumflex artery with the Rotablator device was complicated by "no reflow." Ten days later, a 75% right coronary artery stenosis was successfully managed by balloon angioplasty. On the following day, acute closure of this vessel resulted in death. Gross examination of the heart showed features of recent posterior infarction, and microscopic study revealed atheroemboli in myocardial arterioles. We conclude that high-speed pulverization of atherosclerotic plaque can cause clinically significant emboli.