We examined the extent to which self-forgiveness and forgiveness of others moderated the association of hostility with changes in cognitive impairment over 10 years in a nationally representative sample of adults in the United States. Participants were 1,084 respondents to the Americans' Changing Lives survey, a longitudinal study of American adults. Hostility, self-forgiveness, forgiveness of others, and cognitive impairment were measured at baseline, and cognitive impairment was assessed again at follow-up. Moderated multiple regression analyses tested whether self-forgiveness and forgiveness of others moderated the association of hostility with changes in cognitive impairment over time, controlling for baseline cognitive impairment and relevant sociodemographic and clinical factors. As hypothesized, greater hostility levels at baseline predicted more cognitive impairment 10 years later, β = .08, p < .01. In addition, self-forgiveness at baseline moderated the association between baseline hostility and cognitive impairment at follow-up, β = -.07, p < .01. Decomposing this interaction revealed that hostility significantly predicted increased cognitive impairment at follow-up for individuals with low, β = .15, p < .001, and average, β = .08, p = .001, levels of self-forgiveness but not for persons with high levels of self-forgiveness, β = .03, p = .34. In contrast, forgiveness of others was not a significant moderator. Greater hostility is associated with the development of more cognitive impairment over 10 years, and being more self-forgiving appears to mitigate these hostility-related effects on cognition. Enhancing self-forgiveness may thus represent one possible strategy for promoting cognitive resilience in adulthood. (PsycINFO Database Record (c) 2018 APA, all rights reserved).