PIP: Acquired immunodeficiency syndrome (AIDS) is reviewed for dental practitioners, with an emphasis on oral findings; the clinical course, diagnosis, reporting, treatment, prognosis, transmission, and epidemiology are also covered. HIV infection has an incubation period that may be associated with glandular fever, a prodrome called AIDS-Related Complex (ARC) characterized by lymphadenopathy, low fever, weight loss, night sweats, diarrhea, oral candidosis, nonproductive cough and recurrent infections. AIDS is characterized by opportunistic infections. Over 50% present with pneumocystis carinii pneumonia, 21% with Kaposi's sarcoma, and 6% have both. The AIDS virus causes direct neurological symptoms in some cases. Oral candidosis (thrush) in a young male without a local cause such as xerostomia or immune suppression is strongly suggestive of AIDS. Other oral manifestations are severe herpes simplex, varicella-zoster, Epstein-Barr virus, cytomegalovirus, venereal warts, aphthous ulceration, mycobacterial oral ulcers, oral histoplasmosis, sinusitis and osteomyelitis of the jaw. Hairy leukoplakia, usually seen on the lateral border of the tongue, is probably caused by Epstein-Barr virus. Kaposi's sarcoma, an endothelial cell tumor, is characteristic of AIDS, and in 50% of patients is oral or perioral. Cervical lymph node enlargement will be seen in those with ARC as well as AIDS. No guidelines have been issued by the Department of Health and Social Security for dental surgeons in the UK for reporting AIDS cases. Although HIV virions have been isolated from saliva, there are no known incidents of transmission via saliva. HIV is less likely to be transmitted by needle stick injuries than, for example hepatitis B (25% risk), especially if the blood is from a carrier rather than a full blown AIDS case.