Adoptive families may experience challenges because the parent and child are not biologically related. For example, many adoptive parents realize that their experiences may be different from those of biological parents and may respond to this realization through varying degrees of acknowledging this difference. These thoughts that adoptive parents have about the adoption, or adoptive parenting cognitions, may have implications for adjustment in the adoptive family. Research has been dedicated to examining the relationship between the adoptive parents’ level of acknowledgment of differences and child outcomes; however, fewer studies exist on how this acknowledgment affects the parent-child bond. The current study aimed to longitudinally examine the link between adoptive parent’s level of acknowledgement of differences and the level of attachment between the adoptive parent and adopted child, as perceived by the adolescent. The study also aimed to examine the potential mediating effects of parent-child compatibility, or the match between characteristics of a child and the parenting style of the parent, on this relationship. Data from the current study originate from the Minnesota/Texas Adoption Research Project. Acknowledgement of differences was measured at Wave 1 when the children were 4 to12 years old, adolescent-perceived attachment was measured at Wave 2 when the children were 11 to 20 years old, and parent-perceived compatibility was measured at both waves. Acknowledgement of differences was measured using the Kirk Adoption Questionnaire. Parent-perceived compatibility was assessed using a measure derived from combining four subscales of the Parenting Stress Index. Finally, attachment was measured using the Inventory of Parent and Peer Attachment and a subscale from the Parenting Stress Index. Results of the present study indicated that higher levels of acknowledgement of differences predicted higher levels of adolescent-perceived attachment at a later time point in adoptive father-child dyads but not adoptive mother-child dyads. In addition, parent-perceived incompatibility did not partially mediate this relationship for either mothers or fathers. Implications of the results and areas of further research are discussed