The aim of this article is to consider whether marital or couple therapy can be a useful method of supporting biological treatment, which seems to have been overlooked so far in specialist literature and research. A 21-month process of marital therapy carried out by a couple of psychotherapists was analysed. The sessions lasted one and a half hours and for most of the therapy, they were held once every two weeks. The results of the therapy are promising. The number of relapses and hospitalizations has decreased. For the last four years before the psychotherapy started, the patient had been experiencing one to two fits of psychosis per year and it always involved many months of hospitalizations. For the two years of therapy and one year after its completion, the patient did not experience a relapse of acute psychotic phase and she was not hospitalized. In addition, the quality of the relationship has improved. It seems that marital and couple therapy can become an important part of the treatment of patients struggling with psychoses. To the authors’ knowledge, this method is rarely offered to patients of psychiatric institutions.