In this article we describe three interactions between trauma, post-traumatic stress disorder (PTSD) and psychosis: 1. many patients with psychotic disorders suffered from traumatic life experiences that play an important role in the onset and content of their psychosis; 2. the experience of psychosis as well as its psychiatric treatment may result in post-traumatic stress symptoms; 3. if psychosis and PTSD occur simultaneously, there is a substantial risk for reciprocal negative reinforcement of both symptom groups as well as for potentially on going traumatization. Although these interactions are highly relevant from a clinical perspective, they usually remain unattended in routine care. The three interactions will be illustrated by a case history as well as an impression of the psychological treatment including EMDR. We recommend to pay attention to traumatization and comorbid PTSD in routine care for people with psychosis, as well as to offer them treatment.