A patient with bilateral hairy leukoplakia and candidiasis of the tongue was diagnosed and described. Lesions of the tongue that should be considered in the differential diagnosis include: idiopathic clinical leukoplakia, tobacco-induced leukoplakia, frictional keratosis, edema, lichen planus, galvanic lesions, geographic tongue, maceration, and chronic hyperplastic candidiasis. Hairy leukoplakia occurs predominantly on the tongue as in the patient described. The typical presentation is easily diagnosed but atypical cases may be diagnosed by their lack of response to antifungal treatment and histological exclusion of other lesions. The natural history of hairy leukoplakia needs further study. Hairy leukoplakia has not been reported in patients not infected by HIV; therefore, patients with hairy leukoplakia should be considered highly suspect for subsequent development of AIDS.