Recent decades have witnessed an extraordinary amount of conceptual and empirical work on attachment theory in psychology and psychotherapy. Attachment theory is discussed in the present article as a way of understanding and fostering therapeutic work with 2 other key relationship constructs that have been theorized to be elements of all psychotherapies: client transference and the real relationship existing between the therapist and patient. Fundamental features of attachment, transference, and the real relationship are summarized. Particular emphasis is given to the role of the therapist as a secure base and a safe haven within the real relationship, and to the patient's internal working model as it relates to transference. A case of long-term psychodynamic psychotherapy conducted by the first author is presented to illuminate the 3 main constructs. The case demonstrates both the usefulness of attachment theory and the fact that any single theory cannot explain all of the complex features of a given treatment.