Within psychology and pedagogy is believed that the influence of fairy tales to children's mental health is significant and positive. Most psychologists who have studied the action of fairy tales (Bettelheim, von Franz and others), talk about the fairy tale's irreplaceable influence on child development. Rarely, however, was this opinion investigated. Authors of this paper mainly want to study the actual effect of fairy tales on (developing) psyche of the child in situ and outside the therapeutic encounter. The paper presents results of preliminary research.