This book is a practical guide to the evidence-based cognitive restructuring (CR) for PTSD treatment, which has been specifically designed to meet the unique needs of people with serious mental illness.  Posttraumatic stress disorder (PTSD) is one of the most common disorders in persons with serious mental illness (SMI), leading to more severe psychiatric symptoms, greater impairment in psychosocial functioning, poorer physical health, and higher use of acute care services. Yet despite major advances in the treatment of PTSD in the general population, for many years PTSD has remained under-diagnosed and under-addressed among SMI sufferers, and treatments have been relatively neglected in this population. The cognitive restructuring (CR) for PTSD program described in this book offers clinicians tools for screening, detecting, and treating PTSD in their clients with SMI, in hopes of addressing the great burden of trauma on their lives. Chapters summarize contemporary research and theory regarding the interaction between PTSD and serious mental illness, and provide nuts and bolts strategies for implementing the cognitive restructuring program, with treatment implications for various sub-populations and different kinds of mental illness including schizophrenia, psychosis, and borderline personality disorder. The book's appendix includes educational handouts and worksheets for delivering the CR for PTSD program and tracking clients’ progress throughout. This book also features valuable online resources, including the educational handouts and worksheets translated into Spanish to facilitate using this intervention with Spanish-speaking individuals with SMI, an underserved population with very high rates of trauma and PTSD. A supplemental chapter and practical manual that outline a three-session intervention for PTSD which can be implemented in settings or situations where use of the full CR for PTSD program may not be appropriate are also included online.