Part of our scientific work at the Pre-School Clinic of the Department of Psychiatry here has been to devise ways of better treating young children in groups. A method of Group Psychoanalytic Therapy for young children (4–6) has been worked out and tried by us. No extensive review of the literature has been undertaken, but this method is, as far as we know, original. Our group is composed of five girls aged 4 to 6. Ideally this number should be increased to 7 or 8. Boys were not excluded for theoretical reasons, no male neurotics being on our waiting list at that time. Only psychoneurotics were meant to be accepted in the group, but for practical reasons three cases of mixed aetiology were included. The child therapists have no direct contacts with the parents. The mothers are treated in analytically oriented group therapy, which is centered on their own emotional problems. Their treatment is compulsory in that their children are not treated if they refuse treatment for themselves. Fathers are invited to attend group therapy, but are not pressured into doing so. The therapy room is a standard room of 8 by 16 feet. It contains no equipment or toys of any sort, except for 5 or 6 chairs. Children are seen twice weekly in sessions of 50 to 60 minutes duration. The author is the main therapist, being assisted by a kindergartener. There are advantages to have a female and a male therapist, but the therapy could very well be conducted by only one therapist. The attitude of the therapist is analytic. We do not participate in the children's plays, nor de we suggest any plays. We merely observe and do the necessary interpretative work. Children are left to themselves, and are thus encouraged to initiate spontaneous plays between themselves. The latent content of the plays, the mechanisms of defence, the dynamics of the group and transference constitute our working material for interpretation. In Group Psycho-Analytic Therapy with adolescents or adults, free associations come through verbal communications. Pre-school children will associate just as freely in groups through their collective spontaneous plays. In the technique of play analysis, as perfected by Melanie Klein, the child will use the objects of the therapy room and the therapist for his plays. In group therapy, the objects of the therapy room are replaced by other children, group actions and symbolic plays resulting. The classical theory and technique of psychoanalysis is the theoretical basis of this work, especially its adaption to children by Klein (6). The therapeutic mechanisms in this technique are reviewed, as they appeared in the clinical material from these sessions. The repetition compulsion (4), and the urge to repeat actively what was felt passively is as important here as in other therapies. Splitting of the Ego (5) and the mechanism of double identification in a group is, in our opinion, one of the most important defense mechanisms and subjects of our interpretative work in a group therapy of this kind. Displacement of their libidinal impulses is always operating. Projection of their inner psychic structures, e.g. Super-Ego, onto others in the group, allows us to work this through much more easily than in individual therapy. The specific dynamics of group psychology gives us material for genetic interpretations, a source of material obviously absent in individual play analysis. The mechanisms of defense are worked as in individual therapy. Owing to the dilution of the therapists by the group, transference is longer to appear, but once established is as important as in individual analysis. Transference between children is also present and analysed. One difficulty (3) is that the children may express their instincts in a realistic rather than symbolic way, this being especially true of aggressivity. A controlling, but not prohibitive, action is then needed. Resistance is expressed in meaningless games equivalent to the verbal conversations of older children and adults in group therapy. Acting out is not more a problem here than in other types of group therapies.