The method 3i (intensive, individual and interactive) was worked out and induced in 2004 in France by Catherine de La Presle in order to cure her autistic grandson. Its basic assumptions are derived from the option method by Barry Neil and Samaria Kaufman. The therapy works through play, takes place at child's home, with the involvement of a large number of volunteers. The volunteers guarantee several hours of individual therapeutic relations every day to the child. The method has been defined as educative by its author and her colaborators, it contains, however,a number of elements which could classify it in the area of child psychotherapy. Those elements are; the importance of play and low-intrusive approach, the emphasis on interaction and behavioral dialogue, the ensuring of good and long-lasting mental holding to the child. Through developing relations and stimulating the need for communication with others the development of selfconsciousness and mental capacities is obtained. This method has been applied for some years in the Malthese Aid Centre for Handicapped Children and their Families in Kraków. The goal of this article is to present the principles of the method and its peculiarity, emphasising in particular its psychotherapeutic aspects. The presentation is enriched by a short casuistic illustration.