BackgroundPrisoners have a higher prevalence of substance use disorder (SUD) than the nonincarcerated population. Many studies report that an SUD increases the likelihood of psychotic symptoms/disorders. Inmates, therefore, may be at higher risk for psychotic disorders. ObjectiveThe main objectives of this study were to (1) estimate the prevalence of psychotic symptoms in a sample of male inmates with high levels of SUD and (2) verify if type of abuse or other sociodemographic/clinical features are risk factors of psychotic symptoms. In light of the high prevalence of childhood trauma (CT) among inmates, a further objective was to 3) assess whether exposition to CT can predict psychotic symptoms. MethodWe included three hundred and nineteen male prisoners, admitted to Monza prison between January 2017 and March 2019. We interviewed participants to collect sociodemographic and clinical information. We administered the Brief Psychiatric Rating Scale (BPRS) and the Drug Abuse Screening Test (DAST) to assess the presence of psychotic symptoms and SUD, respectively. Inmates also completed the Childhood Trauma Questionnaire (CTQ). ResultsData were available for 141 inmates. Forty-five prisoners (31.9%) had psychotic symptoms. Multivariate logistic regression analysis showed that a history of previous incarceration (aOR = 2.98, p = 0.034), opioid abuse (aOR = 5.02, p = 0.008), suicide attempts (aOR = 5.55, p < 0.001), and childhood emotional abuse (aOR = 4.11, p = 0.027) significantly increased the likelihood of psychotic symptoms. ConclusionsPsychotic symptoms are widespread among inmates and are associated with specific risk factors. Prison and jail staff should screen for these factors at the start of an inmate's detention to identify subjects at risk of psychotic symptoms.