The present study was carried out to explore the relation between BII phobia and dental phobia. An additional aim was to determine the fainting tendency of dental phobics and BII phobics during an invasive treatment procedure. Participants were 63 patients undergoing treatment in a dental fear clinic, and 173 patients undergoing dental surgery in a university hospital. They completed measures on fears of particular medical and dental stimuli, fainting history, general trait anxiety, dental anxiety, BII anxiety, BII avoidance, and a questionnaire aimed to define a phobia based on DSM-IV criteria. Immediately after treatment information was obtained on exposures to blood or injections, state anxiety, and feelings of faintness during treatment. The results did not indicate any significant relationship between measures of dental anxiety and BII anxiety or BII avoidance. However, 57% of the dental phobic patients could also be classified as BII phobic. The proportion of dental phobics who reported fainting episodes in their past was similar to that of the BII phobics (37%), but none of the participants fainted during treatment. It is concluded that, albeit the level of co-occurrence for both types of phobias is high, dental phobia should be considered as a specific phobia, independent for the BII subtype within DSM-IV. Further, the findings are inconsistent with the notion that individuals with BII phobia have a remarkably high tendency to faint in the presence of their phobic stimuli.