O ral hairy leukoplakia is one of the commonest oral manifestasious ofprogresive Human Immunodeficiency Virus (HIV) infection forwardsAIDS. This lesion is associated with Epstein Barr virus which can spreadrapidly in population group of homoseksual, hemophilic patients,intravenous drugs users, blood transfusion and people committing freeheterosexual life. In these high risk groups, the replication of virus isinfluenced by HIV immunosupresion. The diagnose is based on clinical,serology test and microscopic characteristic. Clinically, hairy leukoplakiaappears as an asymptomatic, greyish white to white, raised, irregularlyshaped lesion that occurs predominantly on the lateral borders of tonguein person with positive HIV antibody. CD4 cell counts below 300cells/mm3 can be used as an indicator of oral lesions in HIV infectionCD4 ceil count becomes lower following the progression of HIV infection.Biopsy showed areas with characteristic balloning cell. In borderlinecases, the diagnosis is established by the presence of EBV in SouthernBlot Hibridization.