In an attempt to go beyond the analysis of children's outcomes in adoption research, the central goal of this study was the analysis of parents' reflective functioning (PRF)—understood as the parents' capacity to reflect upon their own experience as parents, upon their child's experience, and upon the relationships between them— and its connection with parent-child interactions (PCI)—referring to the behavioral patterns observed in verbal and non-verbal interactions between parents and children around a task. To measure PRF, the Parent Development Interview (PDI) was administered to 40 internationally adoptive and 58 non-adoptive parents. To measure PCI, the parent-child dyads were observed while interacting in a co-construction task. The results show reliable psychometric characteristics of PDI instrument for its use with a Spanish sample. Compared to non-adoptive mothers, adoptive PRF was found more articulate and positive, with non-adoptive mothers scoring higher in less positive or openly negative contents. Furthermore, some characteristics of the children (age and gender) and the parents (educational level) were significantly related to PDI factors. For the adoptive dyads, the relationship between PRF and PCI was particularly significant regarding the PDI contents related to the positive perception of the child in the relationship. Moreover, the behaviors in the PCI task were influenced by the child's gender and age at placement. The way parents behave with their children is influenced by their thoughts and feelings about them, and the promotion of parental mind-mindedness may facilitate more constructive interactions.