We investigated whether perceived quality of life is associated with preferences for life-sustaining treatment for older adults. Participants included chronically ill, elderly outpatients (N = 258) and their primary physicians (N = 105). Patients and physicians were independently administered a questionnaire regarding patient quality of life and preferences for cardiopulmonary resuscitation and mechanical ventilation for the patient. Physicians rated patients' global quality of life, physical comfort, mobility, depression, anxiety, and family relationships significantly worse than did patients. Nearly all perceptions of patients' quality of life were significantly associated with physicians' perceptions, but not patients' treatment preferences. Patient-physician agreement on patient global quality of life was not significantly associated with agreement regarding treatment preferences. We conclude that primary physicians generally consider their older outpatients' quality of life to be worse than do the patients. Furthermore, physicians' estimations of patient quality of life are significantly associated with physicians' attitudes toward life-sustaining treatment for the patients. For the patients, however, perceived quality of life does not appear to be associated with their preferences for life-sustaining treatment.