Objectives: People in poor health tend to view life-prolonging treatments (e.g., tube feeding) as more acceptable than do healthier people. Do proxies’ substituted judgments reveal a similar tendency, showing greater acceptance when the elder is in worse health? Method: In a cross-sectional telephone-based survey of 202 elderly individuals and their proxies, preferences for 4 life-prolonging treatments in 7 health prospects were examined in relation to the elder’s current health status, operationalized as number of deficits in activities of daily living. Results: Stronger preferences for life-prolonging treatments in worse-health prospects were expressed by both elders and proxies when the elders’ current health was relatively poor. The interaction effect was at least as pronounced for proxies’ substituted judgment as for elders’ own preferences. Discussion: Findings provide important insight into proxy decision making and have particular implications for proxy decision making on behalf of elders with dementia or other causes of decisional incapacity.