Demographic, medical, and outcome characteristics for 821 do not resuscitate (DNR) patients were compared with 300 age- and sex-matched control patients, and with 230 patients for whom cardiopulmonary resuscitation had been performed. Do not resuscitate patients were more likely to be female and older than cardiopulmonary resuscitation patients and to have a child as next of kin. Although DNR patients in intensive care units had comparable illness levels before and at the time of the order, treatment levels were reduced when the order was written. In general, DNR patients received more nursing care than other patients. Hospital mortality was 59.8% for DNR, 83.9% for CPR, and 1.7% for control patients. We identified diagnosis, prior activity, hospital unit, and employment status as predictors of DNR. According to documentation, 20% of patients participated in the DNR decision. Introduction of a DNR progress note form significantly improved documentation of the DNR process, but further efforts to improve DNR practice and patient participation are recommended.