Adopted adults are presented in the psychological literature as being highly vulnerable to mental health issues. It is probable, therefore, that this vulnerability will affect many aspects of their lives. One such area is their romantic relationships but, to our knowledge, research on this is noticeably sparse, especially with regard to the significance for adoptees’ partners. The objective of the present study was to fill this gap by: (1) comparing the psychological profiles of adoptees’ versus non-adoptees’ partners and exploring their representations of the marital relationship, and (2) investigating the links between the psychological and relational variables in these two groups. To achieve these goals, scales measuring attachment, mental health, dyadic coping and co-parenting were administered to 104 partners of adoptees and 104 partners of non-adoptees. Results showed that there was no difference between the two groups on any of the variables considered. However, a correlation analysis did reveal that dismissing attachment was more closely linked to co-parental conflicts among adoptees’ partners: the more dismissive the non-adopted partner, the fewer the co-parental conflicts. This correlation comparison suggests that dismissing attachment might be a protective factor for co-parental conflicts with the adopted partner, which is in line with some previous studies related to the specificities of attachment among adopted adults.