Bowlby's attachment theory has inspired a dramatic shift in the way we understand the development of the early relationship between infant and caregiver(s). Though almost all infants develop an attachment relationship to their primary caregiver(s), not all of them are able to use their caregiver(s) as a secure base or haven of safety from which to explore the world. Mary Ainsworth was the first to describe in detail the aspects of the caregiving system that are most important for the development of the attachment relationship. During the last decade several studies have started to evaluate the possibility that insensitive and perhaps even inadequate parenting can be effectively ameliorated by interventions. The present article sketches the theory behind attachment-based interventions and reviews the evidence for the effectiveness of such interventions. Finally, the article gives examples of successful preventive as well as therapeutic interventions.