We conducted a prospective survey of attending, resident, and intern physicians who had written a "do not resuscitate" (DNR) order for 93 patients in their care. After writing a DNR order, 11% of respondents would still use chest compression if their patient experienced a cardiopulmonary arrest. Many physicians did not plan to withdraw therapy except intensive care, but most physicians planned to withhold a spectrum of life-sustaining therapies, from hemodialysis (86%) to intravenous fluids (21%). Attending and house-staff physicians generally agreed on whether to withdraw a given therapy or not but frequently disagreed on whether to withhold a therapy or not. After patient discharge or death, 88 charts were reviewed. None of the 88 patients was coded. Physicians initiated 68 life sustaining therapies in 43 patients and discontinued 64 therapies in 34 patients; there was no change in management in 31 patients. We conclude that individual physicians interpret the DNR order differently. These orders often are associated with the discontinuation or noninitiation of life-sustaining therapies other than emergency CPR.