The aim of this paper is to present the usefulness of outpatient psychodrama group psychotherapy. The history of group therapy is described, especially the method of psychodrama created 100 years ago by Jacob L. Moreno. Theoretical assumptions underlying this method, derived from existential philosophy - the meeting theory of Martin Buber and the theory of spontaneity and creativity are discussed. Moreover, the role reverse technique derived from this philosophy and specific to psychodrama is described. The following, most important healing mechanisms in psychodrama were distinguished: reparative experience, the use of augmented reality, catharsis experience, experiencing emotional community with a group, trying out new roles, training social roles, transforming internal roles, expanding awareness and greater self-insight due to feedback. The practice of psychodrama is described by presenting a model of the functioning of an outpatient therapeutic group co-led by the author for ten years. The subsequent phases of the psychodrama session were discussed: pulse, warm-up, playing on stage, role sharing and feedback. The phenomena and processes taking place in psychodrama are illustrated with clinical material - a description of the course of a four hour session of psychodrama.