Physician attitudes towards risk may influence their behavior in critical care situations. To explore this hypothesis, physicians' responses to a questionnaire about risk were compared to their preferences towards "intubation" or "current therapy without intubation" for a hypothetical patient with end-stage lung disease, and to the length of time they performed cardiopulmonary resuscitation before they declared their efforts unsuccessful. When the choices on the questionnaire were framed in terms of loss, choice of the risky alternative was associated with greater preference for "intubation," and with longer duration of resuscitation efforts (both p less than .005). At least part of the variation in physician attitudes and practices towards the care of the critically or terminally ill is associated with measurable psychologic differences among individual physicians.