<p>The relationship between grandparents and adult grandchildren has become more prevalent in contemporary societies. While a growing number of studies have examined the grandparent-adult grandchild relationship in western societies, research in the urban Chinese context is limited. The current study aims to gain a comprehensive understanding about young adults’ childhood and current relationships with their grandparents and how this relationship is related to young adults’ attitudes toward older adults and psychological well-being in the Hong Kong context. We recruited 371 Chinese young adults from Hong Kong and assessed a set of indicators of the grandparent-grandchild relationship (i.e., contact frequency and emotional closeness) in adulthood and childhood. Participants also reported their attitudes toward older adults, life satisfaction, and depressive symptoms. Results confirmed the prevalence of the grandparent-adult grandchild relationship in Hong Kong. Different indicators consistently suggest that stronger bonds with grandparents were related to young adults’ more positive attitudes toward older adults, higher life satisfaction, and fewer depressive symptoms. The findings suggest that grandparents are not only important caregivers in the grandchildren’s childhood, constructive relationships with the grandparents are also significantly related to the grandchildren’s attitudes and psychological well-being after they reach adulthood.</p>