The concept of countertransference (CT) reaction has undergone dramatic changes in definition since its inception at the turn of the century. No longer viewed as a hindrance to effective therapeutic interventions, it has become central to building the therapeutic alliance. However, CT can interfere with the therapeutic task, and this is especially true in forensic settings in which one must help particularly difficult clients. In these cases, the CT must split into two parts in order for the therapist to be clinically effective. The therapist reacts to the individual as both an offender who has violated a societal law and as a client who needs help, separating the client from the behavior. Although not recognized explicitly in the forensic literature, the effects of the dual CT underlie investigations of therapist-offender relationships. This article reviews the concept of CT with specific reference to forensic settings and develops the concept of dual CT.