Although it is generally assumed that HIV transmission does not occur through casual oral contact, persistent reports in the literature and the well-documented case of the Florida dentist (Ou et al., 1992) have served to elevate concerns and interest about the possibility of oral transmission of HIV. The literature suggests that: (1) the presence of infectious virus in the oral cavity is an uncommon event; (2) PCR data indicate that HIV sequences may be present in the oral cavity at reasonably high frequency--further studies are warranted; (3) saliva appears to contain potent anti-HIV activity that may be responsible for the low oral virus titer; and (4) oral secretions are a reliable source for monitoring anti-HIV antibodies. It is clear that the oral cavity will remain a focus for HIV research, in terms of both viral transmission/pathogenesis and for noninvasive diagnosis of the HIV-positive individual.