The study aims to determine the rate of dual diagnosis (DD), examine the most common mental disorders, and determine whether a history of childhood sexual/physical abuse (CSA/CPA) is associated with this phenomenon. One-hundred and eighty inmates from a Spanish prison were assessed using the Mini International Neuropsychiatric Interview and the Addiction Severity Index–6. The data showed that 46.8% of the males and 65.1% of the females had a substance use disorder. With regard to CPA, similar percentages were found in both genders. Nevertheless, rates of CSA were highest in females. Logistic regression analysis was performed by gender. CPA was predictor of DD for males, and CSA was predictor of DD for females, showing the greatest weight. In addition, in both cases, the number of drugs of abuse was an adequate predictor. We can state that these forms of maltreatment are risk factors for the development of a broad range of psychopathological problems.