We examined developmental trends in personality traits over a 42-year time period by using data from the Baltimore Longitudinal Study on Aging (N = 2,359; individuals aged 17-98), collected from 1958 to 2002. Hierarchical linear modeling analyses revealed cumulative mean-level changes averaging about 0.5 SD across adulthood. Scales related to extraversion showed distinct developmental patterns: General Activity declined from age 60 to 90; Restraint increased; Ascendance peaked around age 60; and Sociability declined slightly. Scales related to neuroticism showed curvilinear declines up to age 70 and increases thereafter. Scales related to agreeableness and openness changed little; Masculinity declined linearly. We found significant individual variability in change. Although intercepts differed, trajectories were similar for men and women. Attrition and death had no effect on slopes. This study highlights the use of lower order traits in providing a more nuanced picture of developmental change.