To investigate changes in presentation of oral mucosal lesions in patients with HIV/AIDS attending a dedicated oral medicine clinic over a nine year period. 358 Patients with HIV/AIDS attending a dedicated oral medicine clinic, contained within a genitourinary medicine clinic. Data was collected prospectively for all patients attending the oral medicine clinic, and entered into a database. Lesions were recorded according to the EEC-WHO diagnostic criteria 1991/1993. In 358 patients with 542 lesions, over 54% of the lesions belong within one of the five categories of ulcers, warts, candidiasis, OHL and Kaposi's sarcoma. The major differences in the presentation of the lesions over time were between the ulcers and the warts, but in this series the introduction of HAART did not make a statistical difference. There has been a large reduction in the presentation of oral ulcers, and there appears to be a relative increase in viral papillomata, and a decrease of other mucosal diseases over the period of study. Many of the warts biopsied showed dysplastic changes, and continued follow-up of these patients will be important to determine whether these patients are at increased risk for developing oral squamous carcinoma. Also, proposals are put forward suggesting a need for alteration of the three groups of HIV/AIDS lesions classification suggested by the EEC-WHO consensus. Schlagwörter: HIV, cross sectional study, oral medicine, oral lesions, HPV, oral ulcers