The current proposal aims to bridge research on basic neurocognitive mechanisms of PTSD with intervention research by conducting a randomized controlled trial (RCT) of a cognitive control training program in 80 Veterans with PTSD. Veterans will complete computer-based training exercises designed to specifically target and improve aspects of cognitive control. Veterans will complete the program twice per week for eight weeks. Symptoms will be assessed before and after treatment, as well as at a two month follow up time point. The primary goal of the study is to examine the effect of the intervention on PTSD symptoms and cognitive deficits. Evaluating symptom change as a result of the intervention will provide critical data regarding the utility of this program as a PTSD treatment. If effective, this training program could serve as alternative treatment option for Veterans with PTSD, and could be translated into an easily transportable intervention for dissemination (e.g., through web-based platforms). A secondary goal is to use functional magnetic resonance imaging (fMRI) to better understand the mechanisms by which cognitive training culminates in symptom reduction. If training cognitive control with neurotherapeutics directly enhances functioning of specific neural substrates as hypothesized, improvements in affective processes relying on shared neural regions would also be predicted. Modifying functioning in these substrates with training may thus reduce symptoms by improving neural functioning while processing and managing trauma-related affect and information. Neural systems used for cognitive control targeted in the training described (e.g., dorsolateral prefrontal cortex [dlPFC]) are also recruited when individuals mentally manipulate emotional information, such as when individuals use reappraisal to change the way that they think about negative emotional situations or content. In this study, Veterans will complete a neutral cognitive control task and a reappraisal task while undergoing fMRI before and after completing the training treatment. This will be the first study to evaluate neurobiological mechanisms of this type of training in PTSD, which is a fundamental next step for understanding how to improve the training program and who may be best served by completing it.