Many outcome studies have been conducted to assess the efficacy of virtual reality in the treatment of specific phobias. However, most studies used self-report data. The addition of objective measures of arousal and information processing mechanisms would be a valuable contribution in order to validate the usefulness of virtual reality in the treatment of anxiety disorders. The goal of this study was to document the impact of virtual reality exposure (VRE) on cardiac response and automatic processing of threatening stimuli. Twenty-eight adults suffering from arachnophobia were assessed and received an exposure-based treatment using virtual reality. General outcome and specific processes measures included a battery of standardized questionnaires, a pictorial emotional Stroop task, a behavioral avoidance test and a measure of participants' inter-beat intervals (IBI) while they were looking at a live tarantula. Assessment was conducted before and after treatment. Repeated measures ANOVAs revealed that therapy had a positive impact on questionnaire data, as well as on the behavioral avoidance test. Analyses made on the pictorial Stroop task showed that information processing of spider-related stimuli changed after treatment, which also indicates therapeutic success. Psychophysiological data also showed a positive change after treatment, suggesting a decrease in anxiety. In sum, VRE led to significant therapeutic improvements on objective measures as well as on self-report instruments.