 Intervention: The research will test the effectiveness of integrating evidence-based, efficacious treatments for tobacco use disorder into mental health care for patients with chronic PTSD. Two different methods for delivering smoking cessation treatment will be compared in a randomized, controlled clinical effectiveness trial conducted at four Department of Veterans Affairs VA medical centers. Smokers undergoing mental health care for PTSD who want to quit smoking will be randomly assigned to either 1 guideline-concordant smoking cessation treatment integrated within ongoing mental health care for PTSD, and delivered by mental health providers Integrated Care IC, experimental condition, or 2 specialized smoking cessation treatment, delivered separately from PTSD treatment by a smoking cessation clinic Usual Standard of Care USC, comparison condition. 