The presence of yeasts in oral lichen planus (OLP) lesions was studied in cultivations from 41 OLP patients and by histological examination in 39 of these cases. The histological features of OLP were also recorded. The cultivation results were compared with those of a randomly selected, age- and sex-matched control group without mucosal changes. The extent of growth was recorded as "sparse" (1-10 colonies), "model-rate" (11-40 colonies), or "heavy" (greater than 40 colonies). Yeasts were found to be present on cultures or histologic sections from a total of 19 OLP patients (46%). "Moderate-heavy" growth was obtained in 29% of the OLP cases but in only 7% of the control group. Candida albicans accounted for over 80% of the yeasts. The histological examination revealed only 3 cases of invasive fungal growth. Regarding the criteria of OLP, hyperortho- or hyperparakeratosis and a band-shaped subepithelial infiltration of lymphocytes were present in all specimens, basilar liquefaction degeneration in 87% and an eosinophilic zone in 77%. Local treatment with amphotericin B (Fungizone) in 18 OLP patients with positive findings resulted in subjective relief of symptoms in 89% of the patients. Clinical improvement was seen in 94%. The presence of Candida was significantly correlated to low secretion rate in unstimulated saliva.