Personal growth is essential in the lives of adults of any age and is associated with a variety of well-being outcomes. Building on previous research on psychosocial factors associated with personal growth, the present study aimed to investigate whether and how psychosocial factors (including working, generativity, positive interpersonal relationships, and spirituality) could affect aging adults' personal growth longitudinally. Using three waves of Midlife in the United States data from adults with baseline ages of 20–75, two-level hierarchical linear modeling analyses were conducted to examine the effects of psychosocial factors as well as age and gender on levels and trajectories of personal growth over the span of nearly two decades. All the factors predicted levels of personal growth while positive relationships and generativity had larger effects relative to the others. In addition, some of the effects were moderated by baseline age or passage of time (i.e., aging). Particularly, the moderated effects involving positive relations were multifaceted. Among those with less positive relationships, older people's levels of personal growth remained lower than younger people over time. However, among those with more positive relationships, older people reported lower growth initially but the age difference was no longer confirmed two decades later. In other words, having positive relationships appeared to become increasingly important for aging adults to maintain higher personal growth. These findings suggest shifts in life priorities that could influence personal growth among aging adults, and the implications can be informative for future research and practice. [ABSTRACT FROM AUTHOR]