This systematic review determines the efficacy of virtual reality (VR) therapy for veterans and active service members with combat related post-traumatic stress disorder (PTSD) and identifies common themes among studies utilizing VR. A total of 222 articles were initially considered for this systematic review, and the inclusion and exclusion criteria left 14 articles to be analyzed. A statistically significant or clinically significant reduction in PTSD scores was reported in 64% of the articles after the use of a VR-based therapy. However, no articles provided evidence for VR therapy being statistically better than other forms of therapy in treating PTSD. VR exposure therapy was used in 71% of the studies, making it the most commonly used form of VR therapy, followed by VR graded exposure therapy at 21% and VRET-arousal control at 7%. Limitations and future studies are also discussed.