Pathways by which trauma and post-traumatic stress disorder (PTSD) may affect physical health risk are complex for many reasons: PTSD is multidimensional, with symptoms that can vary over time. Each of the dimensions of PTSD may pose a different risk for co-morbid physical health problems. PTSD is likely to influence a veteran's utilization of health care and thereby is likely to affect health status and compliance with appropriate treatment regimes. Behavioral lifestyle factors, like smoking and drinking, are related both to chronic disease and to PTSD. Models that capture potential pathways for relationships between PTSD and co-morbid physical health outcomes are presented here and literature on PTSD in relation physical disease morbidity and mortality reviewed for studies of veteran populations. Data are compared from a cohort of 3,403 deployed and Vietnam-era veterans who were surveyed in 1984 and 1998 for self-reported medically diagnosed heart disease, hypertension and other chronic illnesses and intensity of PTSD, with analyses adjusted for cigarette smoking and BMI. Post-traumatic stress disorder was significantly associated with diagnoses of heart disease and hypertension during the 15-year observation period. Suggestions for future research on PTSD and co-morbid physical health outcomes are given.