This study examined: (1) the independence of children's attachments to mother and father; (2) the relationships between father and mother quality of attachment and children's social and cognitive self-competence, depression and loneliness; and (3) differences in those relationships by gender. Spanish translations of standardised and self-report measures of mother and father attachment quality, scholastic and social competence, depression and loneliness were administered to 860 middle-class children, aged 8–12 in Buenos Aires, Argentina. Children's attachment security with mothers was only moderately related to their attachment security with fathers, suggesting that these two constructs were somewhat independent. In addition, mother security and father security were uniquely predictive of children's social-emotional outcomes. Availability of and reliance on father most strongly predicted lowered depression scores for children. There were differences in father and mother attachment dimensions and child outcomes by child gender, and these differences can be explained in part by cultural factors.