The aims of this study were to assess types and prevalence of HIV-related oral lesions and to correlate these lesions to the main laboratory parameters such as CD4+ cell count and plasma HIV-RNA. The study population consisted of 104 consecutive HIV+ patients living in Sicily (M=67, 64.4%; F=37, 35.6%; median age=35 years). CD4+ cell count and viral load were measured within 24 h of oral examination. Data were managed and analysed by Epi-Info 6.0. HIV-related oral lesions, as classified by the EC-Clearinghouse, were diagnosed in 35.6% of patients: these were of the Strongly Associated (SA) type in 22.1%, the Less Common Associated (LCA) type in 12.5%, and the Lesions Seen in HIV Infection (LS) type in 3.8%. CD4+ cell counts <200 x 10(6)/l were significantly associated only with SA lesions (P=0.03); median values of CD4+ cell count were also significantly correlated (P=0.02). Viral load, expressed both by median values of copies/ml (P=0.0001) and log10 copies/ml (P=0.0003), was significantly associated only with SA lesions. Treatment failure was significantly correlated to SA lesions (P=0.04). Besides the confirmed correlation with CD4 depletion, the strong association with a high level of viral load could make SA oral lesions a useful tool for identifying progression of HIV infection and could be of value in monitoring antiretroviral therapy.