INTRODUCTION: The overall prevalence of HIV associated oral lesions among adults has decreased since the advent of highly active anti-retroviral therapy (HAART). AIMS AND OBJECTIVES: This study describes the prevalence and types of oral mucosal lesions in adults, who accepted a dedicated oral and dental programme for HIV-infected patients. The incidence of oral lesions and the CD4 cell counts on those patients, were related to cases receiving HAART and to those who were not. DESIGN: This was a retrospective, descriptive cross-sectional study. METHODS: Patients were interviewed, using a structured questionnaire to obtain information regarding medical history, current medications and demographic details. Data relating to CD4 cell counts were extracted from clinical medical records of the patient. In each case, the oral cavity of the sitting patient was examined under artificial light, by a clinician using a mouth mirror. Oral lesions were categorised in accordance with EC-Clearinghouse diagnostic criteria. RESULTS: The prevalence of HIV-associated oral lesions was significantly reduced (p <0.001) in patients receiving HAART. There was, however, no significant difference (p = 0.29) in mean CD4 counts between patients receiving HAART and those not receiving HAART. The presence of oral lesions was statistically significantly, associated with both CD4 counts of <200 cells/mm3 (p<0.001) and the absence of HAART (p = 0.033). CONCLUSIONS: The study confirmed that the incidence of oral lesions and of pseudo-membranous candidiasis in particular, were statistically significantly reduced in patients receiving HAART.