A growing body of literature suggests that Virtual Reality is a successful tool for exposure therapy for anxiety disorders. Virtual Reality (VR) researchers posit the construct of presence, interpreting an artificial stimulus as if it were real, as the mechanism that enables anxiety to be felt during virtual reality exposure therapy (VRE). However, empirical studies on the relation between presence and anxiety in VRE have yielded mixed findings. The current study tested the following hypotheses 1) Presence is related to in session anxiety and treatment outcome; 2) Presence mediates the extent that pre-existing (pre-treatment) anxiety is experienced during exposure with VR; 3) Presence is positively related to the amount of phobic elements included within the virtual environment. Results supported presence as the mechanism by which anxiety is experienced in the virtual environment as well as a relation between presence and the phobic elements, but did not support a relation between presence and treatment outcome