There have been many references in the literature to HIV-related periodontal diseases, which although poorly substantiated, seem to have established them as part of the expected range of HIV-associated conditions. The original studies have produced conflicting reports which may stem from shortcomings in design. Consequently, the picture remains confused with respect to the classification, epidemiology, microbiology, natural history and management of H1V-related periodontal diseases. Future studies should give greater attention to sampling methods, the use of control groups and defining criteria. This will allow comparison of data between centres and facilitate study of what may be an uncommon disease.