Forensic psychiatry deals with a treatment of offenders of unlawful deeds that were assessed as not guilty by reason of insanity. These people are sent for an involuntary treatment by the court. Therapists who treat these people are obliged to inform the court about the process of treatment. These two characteristics are basic problems in the dynamic group psychotherapy of forensic patients. This manuscript deals with specific issues of dynamic group psychotherapy in forensic settings: how to do dynamic group psychotherapy in involuntary treatment setting, what are specific countertransferential reactions due to the fact that group members all committed an unlawful deed, the introduction of the third party (the court) in the therapeutic process, homogenous group in regard of diagnostic categories, large number of group members with antisocial personality disorder, feelings of (in)security in a group of perpetrators. The author's experience is that, although there are many specificities of group psychotherapy with forensic patients, the basic therapeutic techniques are the same, with the important task of continuous and thorough analysis of own (countertransferential) emotional reactions.