Cognitive-behavioural therapy is often used for anger treatment. An important element of this therapy is exposure to anger evoking stimuli. In this paper virtual reality is put forward as a technology that can effectively create these stimuli by exposing patients to social scenes that include anger stressors such as aggressive dialogues with virtual characters or arousing surrounding with loud music or flashing light. Applying a situated cognitive engineering approach a prototype system was developed which allowed a therapist to control these stressors. To evaluate the prototype an experiment was conducted in which participants, 18 non-patients and 2 patients, were exposed in a virtual environment to three types of social scenes: (1) a passive dialogue, (2) an aggressive dialogue, and (3) an aggressive dialogue with arousing surrounding. Results showed that these conditions had a significant effect on participants’ galvanic skin response and the type of verbal reply towards the avatar. This effect was significant larger for the two patients than the non-patient group. In addition, evaluation of the therapist user interface suggested that most interaction components were relatively easy to use.