A total of 32 HIV-infected, predominantly ethnic Chinese individuals from Hong Kong were examined for oral mucosal lesions over a period of 1 year. The commonest oral lesion found was minor aphthous ulceration (27.4%), while xerostomia (17.8%), ulceration NOS (not otherwise specified; 12.3%), hairy leukoplakia (11.0%) and erythematous candidiasis (6.9%) were less frequent; Kaposi's sarcoma was notable for its absence. When the relationship between the number of oral lesions with age, risk group, medication taken, CDC staging and CD4+ count of the study group was investigated, a significantly higher number of oral lesions was associated with use of AZT, homosexuals and CDC stage IV; in contrast, a smaller number of lesions was found in those on antiparasitics and multivitamins (all P<0.05). When compared with studies from other parts of the world, the frequency of oral lesions appeared to be less common in the current study group. However, due to a lack of similar studies from the Asian region, especially in ethnic Chinese, it is not clear whether this difference could be attributed to racial, social or geographic factors.