Some dialysis units have a policy of performing cardiopulmonary resuscitation (CPR) on all patients who experience cardiac arrest while undergoing dialysis. However, to perform CPR on patients who do not want it is contrary to ethics and the law. We interviewed hemodialysis patients in 12 units in Missouri, New York, and West Virginia to learn their attitudes about CPR. Four hundred sixty-nine of 830 patients (57%) agreed to be interviewed. Eighty-seven percent of patients wanted to undergo CPR if cardiac arrest were to occur while undergoing dialysis. Patients who had seen CPR on television were more likely to report that they knew what CPR was (94% versus 68%; P < 0.001) and to want CPR (88% versus 78%; P = 0.033). Thirteen percent of patients did not want CPR if cardiac arrest were to occur while undergoing dialysis. Compared with patients who wanted CPR, those who did not were older (69 versus 59 years; P = 0.026), had more comorbid conditions (2.0 versus 1.5 comorbid conditions; P = 0.016), and were more likely to have a living will (61% versus 43%; P = 0.01), be widowed (36% versus 20%; P = 0.026), and live in a nursing home (9% versus 3%; P = 0.017). Blacks were significantly more likely to want CPR than whites (adjusted odds ratio, 6.56; 95% confidence interval, 2.57 to 22.27). Only 20 of 58 patients (35%) who did not want CPR were certain they had a do-not-resuscitate order in their dialysis chart. Ninety-two percent of patients who wanted CPR agreed that patients who did not want CPR should have their wishes respected by the dialysis unit. We conclude that most dialysis patients want to undergo CPR, but also want other patients' preferences not to be resuscitated to be respected. Dialysis units need to do a better job of identifying patients who prefer not to be resuscitated and respecting their wishes in the event of cardiac arrest while undergoing dialysis. Most importantly, nephrologists and dialysis unit staff need to educate dialysis patients about the poor outcomes with CPR so that dialysis patients' decisions about CPR are informed.