In correctional settings there has been found a strong connection between PTSD and substance abuse disorders among inmates. In 1993, the Seeking Safety treatment therapy was developed to address the dual diagnosis of substance use disorder and PTSD. Seeking Safety offers 25 treatment topics focusing on cognitive, behavioral, and interpersonal issues. The Seeking Safety treatment is based on five principles: (1) safety as the priority of treatment; (2) integrated treatment of PTSD and substance abuse; (3) a focus on ideals; (4) content areas of cognitive, behavioral, interpersonal, and case management; and (5) attention to therapist processes. Four evaluative studies have been conducted on Seeking Safety, including one in a correctional setting. The first was a pilot study with Seeking Safety in group format. The second evaluated Seeking Safety in a correctional setting. The third compared Seeking Safety with relapse prevention treatment with a treatment-as-usual control condition in a randomized controlled trial. The fourth and final study evaluated a combination of Seeking Safety and exposure therapy for PTSD in a sample of five men. Improvements were identified in drug use, family/social functioning, trauma symptoms, anxiety, dissociation, sexuality, hostility, overall functioning, meaningfulness, and feelings and thoughts related to safety. Treatment attendance, satisfaction, and alliance were very high.