Relationships between trauma symptoms and delusional ideation were explored in a forensic sample. A between-subjects design compared low and high trauma scoring patients on measures of delusional ideation and paranoia. A within-subjects design examined associations between trauma-related cognitions, delusional ideation and paranoia. Thirty-four participants were recruited from a number of secure units. Participants' “worst trauma” was identified using a self-report analogue scale. Self-report measures of trauma symptoms, trauma-related beliefs, delusions and paranoia were completed. Thirteen patients scored above the cut-off on the trauma measure, indicating a high rate of trauma symptoms. The most frequently cited worst traumas were committing an offence and the experience of psychosis. Correlational analyses revealed positive associations between traumatization and intensity of delusional ideation and paranoia. Trauma-related negative cognitions about the self were positively associated with level of delusional ideation, associated distress, and preoccupation. Negative cognitions about the world were associated with paranoia. Findings provide some evidence for associations between traumatization and delusional ideation and paranoia in this population. Future research should aim to replicate and extend the study, using a larger sample size and diagnostic measures of post-traumatic stress disorder (PTSD).