The principles of medical decision-making suggest that values and preferences of patients should be important determinants of the use of treatments. From data collected during the SUPPORT study, we determined whether seriously ill patients' preferences for pain control expressed earlier in their hospitalization were associated with later pain. Of the 2820 patients who gave both earlier interviews about their pain care preferences and willingness to live permanently in pain, and later interviews about pain, 1388 (49.2%) told us that they preferred a course of care aimed at relieving pain, and 1426 (50.6%) were very unwilling or would rather die than be permanently in pain. At the later interview, 655 (23.2%) reported that they had extremely severe or moderately severe pain. After adjustment for other variables associated with later pain, neither preference for pain control nor willingness to live permanently in pain was associated with later pain.