It is sometimes difficult in clinical practice to identify carriers of the AIDS virus. Such identification is of unquestionable value in oral pathology, both for determining the pathogenesis of certain lesions and for assessing their significance to the patient. We evaluated several commercially available diagnostic techniques for the detection of anti-HIV antibodies in serum, and examined the feasibility of adapting such techniques to tests on saliva. The technique chosen for experimental adaptation required only slight modifications for use with this medium. We compared the results obtained in serum from intravenous drug users with a western blot assay designed to detect p24 viral protein, against the findings with a test designed to detect salivary antibodies. The likelihood of cross-reactions in saliva containing high concentrations of other antiviral antibodies was also studied. The specificity and sensitivity of the modified saliva test were 100% and 96% respectively, and no cross-reactions were observed.