This study examined whether positive sentiment override (greater positive appraisal of spouse's affiliative behavior than is warranted by observed behavior) occurred more frequently in older compared with middle-aged married couples and whether age differences were mediated by older adults' greater marital satisfaction when controlling for optimism. Participants included 270 middle-aged (40-50 years old) and older (60-70 years old) couples who discussed a marital disagreement and completed an errand task. Couples provided appraisals of their spouse's affiliation, and the authors coded affiliative interactions using the structural analysis of social behavior. Hierarchical multivariate linear modeling indicated that older husbands and wives viewed their spouse's behavior as more positive during disagreement interactions than did independent observers; in the errand task, only older wives demonstrated positive sentiment override. Age differences in positive sentiment override were mediated by marital satisfaction, even when controlling for optimism. The results are consistent with theories of emotion regulation, such as socioemotional selectivity theory, that suggest that older adults are biased toward the positive aspects of close relationships.