This study assessed the effects of a session of eye movement desensitization and reprocessing (EMDR) with auditory alternating bilateral stimulation (ABS) using functional magnetic resonance imaging (fMRI) of brain activations. A case study was conducted with a female participant who was suffering from posttraumatic stress disorder following a severe assault. The fMRI scan began with safe-place imagery, for purposes of comparison, and then attention to the trauma memory without ABS. After this, ABS was provided as she began using EMDR procedures to process the traumatic memory. At postsession, the traumatic memory showed robust and significant changes on self-report measures. The initiation of the EMDR protocol with provision of ABS was associated with a marked change in brain activation within the prefrontal cortex demonstrating a ventromedial shift. The authors argue that the structure of the EMDR protocol encourages such a ventromedial activation, which is then intensified by ABS to overcome the block to information processing that has been preventing natural healing from occurring spontaneously.