Building on the attachment theory and extending prior research that has hinted strongly at the important influence of social relationships on self-esteem, this study examined the simultaneous effect of adolescents’ attachment to parents and peers on self-esteem. To test our hypotheses, we collected data from a sample of 267 adolescents. We used polynomial regression coupled with response surface analysis to assess the (in)congruence effect of adolescents’ attachment to parents and peers on self-esteem. The results of polynomial regression analysis show that the congruence effect of attachment to parents and peers did not relate to adolescent self-esteem. However, self-esteem is high when attachment to both parents and peers is at a high level rather than a low level. Moreover, results show that attachment to parents is more significant than attachment to peers in developing adolescents' self-esteem. Interpretation of findings and theoretical contribution of congruence perspective to attachment theory and self-esteem literature are discussed.