We conducted a retrospective cohort study of US service members who sustained combat injuries while deployed in support of military Background-During the conflicts in Iraq and Afghanistan, 52 087 service members have been wounded in combat. The long-term sequelae of these injuries have not been carefully examined. We sought to determine the relation between markers of injury severity and the subsequent development of hypertension, coronary artery disease, diabetes mellitus, and chronic kidney disease. Methods and Results-Retrospective cohort study of critically injured US military personnel wounded in Iraq or Afghanistan from February 1, 2002 to February 1, 2011. Patients were then followed until January 18, 2013. Chronic disease outcomes were assessed by International Classification of Diseases, 9th edition codes and causes of death were confirmed by autopsy. From 6011 admissions, records were excluded because of missing data or if they were for an individual's second admission. Patients with a disease diagnosis of interest before the injury date were also excluded, yielding a cohort of 3846 subjects for analysis. After adjustment for other factors, each 5-point increment in the injury severity score was associated with a 6%, 13%, 13%, and 15% increase in incidence rates of hypertension, coronary artery disease, diabetes mellitus, and chronic kidney disease, respectively. Acute kidney injury was associated with a 66% increase in rates of hypertension and nearly 5-fold increase in rates of chronic kidney disease. Conclusions-In Iraq and Afghanistan veterans, the severity of combat injury was associated with the subsequent development of hypertension, coronary artery disease, diabetes mellitus, and chronic kidney disease.