Extensive cross-cultural evidence supports the conclusion that children and adults everywhere understand themselves to be cared about (accepted) or not cared about (rejected) by the people most important to them (e.g., parents) in four ways. These four ways include the perception of warmth/affection (or coldness/lack of affection), hostility/aggression, indifference/neglect, and undifferentiated rejection. In addition, extensive cross-cultural evidence supports the conclusion that psychological adjustment of children and adults everywhere tends to be affected in the same way when they feel their attachment figures do not care about or love them (i.e., reject them). About 11 prior meta-analyses have documented these conclusions about the relationship between psychological maladjustment and the experiences of parental coldness/lack of affection, hostility/aggression, and indifference/neglect, among offspring. However, the cross-cultural link between psychological maladjustment and undifferentiated rejection has not heretofore been explored via meta-analysis. That is the purpose of this study. It examined relations among children’s current perceptions and adults’ remembrances of parental undifferentiated rejection in childhood, and offspring’s psychological adjustment. The meta-analysis was based on 102 studies (89 published and 13 unpublished) from 17 countries involving 24,003 respondents. Results showed that both maternal and paternal undifferentiated rejection correlated significantly in all countries with overall psychological maladjustment of both children and adults. However, maternal undifferentiated rejection had a significantly stronger relationship with both children’s and adults’ psychological maladjustment than did perceived paternal undifferentiated rejection. Perceived maternal undifferentiated rejection also had a significantly stronger relationship with children’s psychological maladjustment than with adults’ psychological maladjustment.