Vicarious traumatization (VT) is described in the literature as a transformation that occurs in the therapist as a result of working with a client's traumatic experiences. The primary symptoms of VT are disturbances in tolerance for strong emotions, mental frame of reference, interpersonal relationships, psychological needs, and identity. A number of mechanisms of VT have been suggested in the literature, including countertransference, empathic engagement with the client, and cognitive adaptations such as those described in constructivist self-developmental theory. The latter theory asserts that the adaptation observed in trauma survivors is a product of their pretrauma personality characteristics and the prominent aspects of the traumatic events being experienced within the context of relevant social and cultural variables. These elements combine to redefine an individual's mental outlook and perceptions/interpretations of reality. A recent survey of trauma in therapists found that just over 50 percent of sex-offender and survivor therapists reported symptoms of trauma reactions in the clinical range. Factors related to VT in sex-offender therapists pertain to client characteristics, therapist characteristics, and setting and therapy characteristics. The strongest positive predictors of VT in sex-offender therapists have been identified as the therapist's use of positive and negative coping strategies. This suggests that training for sex-offender therapists should include instruction in the possible effects of VT and guidelines for addressing VT reactions. Institutions and professional organizations can increase the opportunity for peer supervision and discussions of VT. 48 references and 4 suggested readings