In some intensive care units (ICUs), fewer patients who die now undergo attempts at cardiopulmonary resuscitation (CPR), and many more have life support actively withdrawn prior to death than did a decade ago. To determine the frequency of withdrawal of life support, we contacted every American postgraduate training program with significant clinical exposure to critical care medicine, asking them prospectively to classify patients who died into one of five mutually exclusive categories. We received data from 131 ICUs at 110 institutions in 38 states. There were 6,303 deaths, of which 393 patients were brain dead. Of the remaining 5,910 patients who died, 1,544 (23%) received full ICU care including failed cardiopulmonary resuscitation (CPR); 1,430 (22%) received full ICU care without CPR; 797 (10%) had life support withheld; and 2,139 (38%) had life support withdrawn. There was wide variation in practice among ICUs, with ranges of 4 to 79%, 0 to 83%, 0 to 67%, and 0 to 79% in these four categories, respectively. Variation was not related to ICU type, hospital type, number of admissions, or ICU mortality. We conclude that limitation of life support prior to death is the predominant practice in American ICUs associated with critical care training programs. There is wide variation in end-of-life care, and efforts are needed to understand practice patterns and to establish standards of care for patients dying in ICUs.