Children who have been adopted or fostered are at high risk of experiencing interpersonal difficulties and placement breakdown may occur if these difficulties are not addressed through interventions. The aim of this review was to identify the impact of attachment interventions with foster and adoptive parents on children's behavioural, emotional and relational functioning. A systematic search process was undertaken; electronic databases were searched; key journals were hand searched; reference lists of included articles were searched; and authors who have published work in the field were contacted. Ten studies met the inclusion criteria. There is some evidence to support the positive impact of these interventions for children, particularly young children aged six months to six years. However, overall, the studies were of relatively poor methodological quality, making conclusions about the efficacy of these interventions difficult. Further research is therefore required to draw clearer conclusions about the impact of attachment interventions for fostered and adopted children. Copyright © 2014 John Wiley & Sons, Ltd. ‘Ten studies met the inclusion criteria’ Key Practitioner Messages A number of the reviewed studies reported positive outcomes in child behavioural functioning and to a lesser degree in emotional and relational functioning following intervention. Interventions focused on constructs such as parental sensitivity, attunement to the child and the impact of abuse and neglect on attachment to new caregivers. When quality criteria were applied, two studies focused on children aged six months to six years were found to be methodologically strong, providing some evidence for the benefit of early attachment‐based interventions within this population. ‘Two studies focused on children aged six months to six years were found to be methodologically strong’