Co-occurring posttraumatic stress disorder (PTSD) and alcohol use disorders have become increasingly prevalent in military populations. Over the past decade, PTSD has emerged as one of the most common forms of psychopathology among the 1.7 million American military personnel deployed to Iraq and Afghanistan in Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), and Operation New Dawn (OND). Among veterans from all eras, symptoms of PTSD have been highly correlated with hazardous drinking, leading to greater decreases in overall health and greater difficulties readjusting to civilian life. In fact, a diagnosis of co-occurring PTSD and alcohol use disorder has proven more detrimental than a diagnosis of PTSD or alcohol use disorder alone. In order to effectively address co-occurring PTSD and alcohol use disorder, both the clinical and research communities have focused on better understanding this comorbidity, as well as increasing treatment outcomes among the veteran population. The purpose of the present article is threefold: (1) present a case study that highlights the manner in which PTSD and alcohol use disorder co-develop after trauma exposure; (2) present scientific theories on co - occurrence of PTSD and alcohol use disorder; and (3) present current treatment options for addressing this common comorbidity.