Objectives. To study how traumatized refugees, their therapists, and their interpreters perceive both curative and hindering factors in psychological therapy, thereby highlighting the mediators of change in a transcultural clinical setting. Design. Four experienced clinical psychologists affiliated to two centres for the rehabilitation of traumatized refugees, were asked to select their two 'most successful' and two 'least successful' cases by going back to all the cases that they had concluded within the last 2 years, a pool of approximately 200 patients. The selected 16 patients, their therapists, and their interpreters were invited to semi-structured, in-depth, individual interviews with the aim of acquiring more knowledge on what had been helpful and what not helpful in the psychological treatment. Method. The senior author who conducted the interviews was not aware of whether the patient belonged to the 'successful' or 'unsuccessful group' prior to the interview. All interviews were audio taped. A qualitative phenomenological approach was used in the analysis of the data. The data were analysed (1) triad by triad for the 16 triads consisting of a patient, his/her therapist, and his/her interpreter, and (2) separately for each of the three groups of respondents. The analysis involved going through each protocol sentence by sentence and developing key-concepts for the therapeutic interventions and for the interpersonal relations. When the generation of key-concepts was finalized, the material was analysed for a second time, in order to place the relevant data under the key-concepts/categories. The categories and illustrative verbatim quotations from the interviews are presented in separate tables for the three groups. Results. The relationship between the therapist, patient, and interpreter, and the development of trust and a good working alliance was seen by all as the most important curative factor. Psychoeducative methods, cognitive interventions, as well as the provision of practical help and advice were also regarded as curative and facilitating factors. Hindering factors fell into the following five categories: factors related to the patient, to the therapist, to the interpreter, to the therapeutic method itself, and to factors external to the therapy. Therapists and interpreters considered severe psychopathology and substance abuse in addition to PTSD; chronic pain and physical illness; lack of motivation for treatment; and overwhelming social and/or economic problems as obstructive factors for the establishment of a working alliance and more generally for a successful outcome. As to the patients who did not benefit from the treatment, the unsuitability of a psychological treatment for their symptoms, and social and economic problems were seen as the main hindering factors. Conclusion. The therapeutic or working alliance is a common element of all types of psychological treatments, and is generally considered as a 'non-specific' factor. There are grounds to modify this view in working with traumatized and tortured patients from different cultural backgrounds. In cases where patients have experienced humiliation and evil, and now live in exile, the establishment of a relation of trust in fellow human beings is the first aim of the treatment. The article argues that the professional's compassion constitutes a primary factor in the therapeutic process in such cases. The risks of overinvolvement in the treatment of heavily traumatized patients are well described in the literature, and have also appeared in this study. In psychotherapy research, strong personal commitment is seldom mentioned by therapists for fear of its being considered unprofessional or unethical. However, a strong commitment can be of value, not only for the patients, but also for the therapists and interpreters themselves. The results of this study suggest that deep compassion on the part of the professionals is widespread in the treatment of traumatized patients, and that it is considered as a healing factor by most patients, interpreters, and therapists. [ABSTRACT FROM AUTHOR]