To date, there have been no long-term longitudinal studies of continuity and change in narcissism. This study investigated rank-order consistency and mean-level changes in overall narcissism and 3 of its facets (leadership, vanity, and entitlement) over a 23-year period spanning young adulthood (Mage = 18, N = 486) to midlife (Mage = 41, N = 237). We also investigated whether life experiences predicted changes in narcissism from young adulthood to midlife, and whether young adult narcissism predicted life experiences assessed in midlife. Narcissism and its facets showed strong rank-order consistency from age 18 to 41, with latent correlations ranging from .61 to .85. We found mean-level decreases in overall narcissism (d = -0.79) and all 3 facets, namely leadership (d = -0.67), vanity (d = -0.46), and entitlement (d = -0.82). Participants who were in supervisory positions showed smaller decreases in leadership, and participants who experienced more unstable relationships and who were physically healthier showed smaller decreases in vanity from young adulthood to middle age. Analyses of the long-term correlates of narcissism showed that young adults with higher narcissism and leadership levels were more likely to be in supervisory positions in middle age. Young adults with higher vanity levels had fewer children and were more likely to divorce by middle age. Together, the findings suggest that people tend to become less narcissistic from young adulthood to middle age, and the magnitude of this decline is related to the particular career and family pathways a person pursues during this stage of life. (PsycInfo Database Record (c) 2020 APA, all rights reserved).