Attachment is relevant to institutionalized treatment and the therapeutic process in three identifiable ways: (1) patients bring their mental representations of previous and existing attachment relationships to the treatment; (2) attachment is relevant to the extent to which a therapeutic alliance is established and maintained, both in terms of the mental representations of attachment in the patient and in the therapist and how these influence interactive behaviour and expectations in each partner to the therapeutic work; (3) the outcome of the treatment may be related to attachment; for example, when institutional experiences have an enduring impact on attachment representations and the future attachment behaviour of the patient. However, this brief review of attachment concepts reveals that several theoretical, conceptual and empirical questions remain to be answered before evidence-based clinical attachment guidelines can be formulated concerning patient-staff relationships.