This study examined the influence of surrogate gender on the accuracy of substituted judgments about the use of life-sustaining treatment in a sample of 249 older adults and their self-selected surrogate decision-makers. Overall, wives were more accurate than husbands at predicting their spouses' treatment wishes. Surrogates' perceptions of their own abilities did not differ by gender but, among patients, husbands had more confidence than wives in their spouses' accuracy as, and comfort being, a surrogate. The results are discussed within the context of broader gender differences in caregiving and highlight the need for more research regarding predictors of surrogate accuracy to assist patients in selecting surrogates who will help protect their end of life wishes.