Acrophobia is a chronic highly debilitating disorder preventing sufferers from engaging with high places. Its aetiology is linked to the development of mobility during infancy. We evaluated the efficacy of various type of movement in the treatment of this disorder within a virtual reality environment. Four men and four women who were diagnosed with acrophobia were tested in a virtual environment reproducing the balcony of a hotel. Anxiety and behavioral avoidance measures were taken as participants climbed outdoor stairs, moved sideways on balconies or stood still. This took place in both a real and virtual environment as part of a treatment evaluation study. Participants experienced an elevated level of anxiety not only to increases in height, but also when required to move laterally at a fixed height. These anxiety levels were significantly higher than those elicited by viewing the fear-invoking scene without movement. We have demonstrated a direct link between any type of movement at a height and the triggering of acrophobia in line with earlier developmental studies. Given this is suggested that recalibration of the action-perception system, aided by virtual reality, can be an important adjunct to standard psychotherapy.