In considering the contributions of attachment theory and research to individual psychotherapy with adults—the focus of this article—the starting point is the therapist’s role as a secure base from which the patient can safely engage in self-exploration. I discuss the barriers to the patient’s ability to subjectively experience the therapist as a secure base and the necessary therapeutic ingredients for these barriers to be attenuated. I also discuss the nature of therapeutic action from the perspective of a therapeutic approach informed by attachment theory and research. And finally, there is some discussion devoted to the contributions of attachment theory and research to an understanding of psychopathology.