There has been controversy surrounding the principles of bite mark analysis, and also the opinions reached by forensic odontologists. The purpose of this study was to assess the consistency of opinions formed by forensic odontologists, both for individual odontologists after a period of time, and between odontologists. 23 forensic odontologists participated, and opinions on 4 cases per member were requested. The request was then repeated after a 8 week period. Results highlighted an inconsistency in opinions between odontologists, and also an inconsistency in opinion for individual members over time, even for experienced odontologists. Inconsistencies varied from whether the mark could be from human or animal, and also from adult or child. In conclusion, the authors recommend that bite mark evidence should be treated with caution.