Group therapy in the treatment of psychiatric patients in a day hospital Introduction: Psychiatry is a branch of medicine that combines the treatment and the research of mental disorders. The quality of life of patients with mental disorders is often impaired, since the disease affects their lifestyle. Via pharmacotherapy and psychotherapy, the psychiatrist strives to provide the patient with the highest possible level of functionality while maintaining and/or ensuring they achieve a better quality of life. Procedure: By analyzing and synthesizing the collected data from Croatian and foreign professional literature, is showed the importance and efficiency of group therapy in a day hospital. Overview: Psychotherapy combines the application of procedures with a tendency to alleviate the intensity of, or completely eliminating certain psychological disorders with the modulation of inadequate patterns of behavior. Psychotherapy focuses both on strengthening the existing, and the development of new, healthy defense mechanisms. Through participation in group therapy, patients are encouraged to verbalize their problems, without experiencing stigmatization or judgement. Group therapy in a day hospital provides patients with the opportunity to participate in group therapy according to an agreed schedule, while they spend the rest of their time in their everyday environment, to which they are accustomed. This reduces the stress that comes with hospitalization to a minimum, since the patient does not change his environment and is not spending a great amount of time in an unfamiliar environment. Conclusion: As humans are deeply dependent on belonging to a group, group therapy helps in the process of modulating and expressing feelings and modulating thoughts. With the guidance of a psychiatrist or nurse, during group therapy in a day hospital, people with mental disorders acquire new knowledge that would help them create quality relationships with others, but also with themselves. Psychotherapy helps them achieve a positive change and a better quality of life.