A newly established formal ethics consultation service in a university teaching hospital was prospectively evaluated. A physician-ethicist interviewed and examined patients, interviewed family and others as needed, and entered a formal consultation note in the medical record. The requesting physician and the consultant independently completed structured questionnaires. Fifty-one consultation requests were received from 45 physicians from seven departments between July 1, 1986, and June 30, 1987. Seventeen (33%) of 51 patients were in the intensive care unit, and 19 patients (37%) were fully oriented at the time of consultation. Overall, 61% of the patients survived to leave the hospital. The requesting physician sought assistance with withholding or withdrawing life-sustaining treatment in 49% of cases, with resuscitation issues in 37%, and with legal issues in 31%. Assistance with more than one issue was sought in 39 cases (76%). In 36 cases (71%), the requesting physician stated that the consultation was "very important" in patient management, in clarifying ethical issues, or in learning about medical ethics. We conclude that ethics consultation performed by physician-ethicists provides useful, clinically acceptable assistance in a teaching hospital.