Infant attachment and mother–child interaction were evaluated for 65 primiparous women and their singleton infants conceived through in vitro fertilisation (IVF) and a control group of 61 women and their infants conceived naturally. The sample was enrolled during pregnancy as part of a longitudinal study. At 12 months postpartum, security of infant attachment was assessed using the Strange Situation procedure, and mother–child interaction was assessed in a free play context using the Emotional Availability Scales. IVF children demonstrated predominantly secure attachment relationships with their mothers (64.6% IVF, 55.9% controls), and there were no significant between-group differences in the proportion of IVF compared to control group children classified in any of the secure or insecure attachment groups. Furthermore, there were no significant group differences on maternal (sensitivity, structuring, hostility) or child (responsivity, involving) dimensions of interaction during play. The majority of IVF mothers (86%) were sensitive and their infants responsive (91%). Contrary to expectation, mother's ratings of greater anticipated infant difficultness assessed during pregnancy and higher ratings of infant temperament and behaviour difficulty assessed at 4 and 12 months postpartum were associated with secure attachment relationships and more optimal mother–child interaction in both the IVF and control groups.