The aim of this paper is to discuss the impact and significance of religious beliefs on the dissociation and somatization symptoms presented by a hospitalised female patient. A 16-year-old girl was hospitalised at the Developmental Age Psychiatry and Psychotherapy Clinical Ward (The Clinical PiPWR Ward) for observation; she had been referred from the Regional Acute Poisoning Centre where she had been admitted upon taking some medications. For two years she had been subjected to exorcisms due to possession by the Evil. Religious convictions had been sustained and enhanced by the patient's parents as well as a local Catholic community. The observation and diagnosis at the PiPWR Clinical Ward revealed mixed dissociation and somatization disorders as well as an abnormally shaping personality. The presented case, on the basis of the clinical observation and the analysis of literature on the subject, led to the following conclusions: the emotional issues and the system of religious beliefs influenced the shape of symptomatology, enforced the functioning of immature defensive mechanisms and intensified the dissociation and somatization disorders in the patient. The diagnosed mental disorders require that the girl should undergo individual and family psychotherapy.