Antenatal attachment representations (Adult Attachment Interview classification and reflective function score) were assessed in 25 couples and 3 solo mothers. Infant-parent interaction was observed separately for mothers (N = 21) and fathers (N = 17) at 6 months postpartum, from which measures of parents' ability to comment accurately on their infants' internal states (mind-mindedness) were obtained. Infant-parent attachment security was assessed at 12 (mother, N = 18) and 15 (father, N = 15) months. Autonomous parental Adult Attachment Interview classification, higher reflective function, and infant-parent attachment security were associated with greater mind-mindedness, with effects stronger for fathers than for mothers. A preliminary longitudinal analysis suggested that parental mind-mindedness may help explain intergenerational transfer of attachment security.