We investigated changes in midlife parents' intergenerational ambivalence toward a focal child and its influence on their psychological well-being over 14 years, as the focal child moved from adolescence into young adulthood. We estimated growth curve models using three waves of data from the National Survey of Families and Households (N = 1,510 parents aged 35-54 years at Time 1). Parental ambivalence declined over time, equally among mothers and fathers. The prediction from ambivalence theory that children's attainment of adult statuses reduces parental ambivalence received only modest support. Only the focal child's marriage reduced parental ambivalence. The focal child's lifestyle--behavioral problems during adolescence still elevated ambivalence 14 years later, albeit less so. For its part, intergenerational ambivalence counteracted trends toward declining depressive symptoms and greater happiness for mothers and fathers alike, and its effects remained constant over time.