There are external and internal criteria determining the indication for group psychoanalysis. The external factors are connected with the patient's reality. The internal criteria are based on the patient's psychic structures. A decisive point is the state of the patient's ego-functions. Some ego-functioning must be expected for qualifying the patient for group therapy. The patient must be able to oscillate between his own individual experience and the common developmental history of the group. Certain defences are described as being contraindications for group treatment.