Objective: To evaluate the usefulness of exfoliative cytology as a diagnostic tool for patients with clinical symptoms of desquamative gingivitis. Method and Materials: Fifteen patients clinically diagnosed with desquamative gingivitis were evaluated. At their first visit, a cytologic smear was performed on the gingival lesion. On their second visit, a gingival biopsy was obtained from the perilesional site. Control smears were taken from 15 patients who had no oral lesions. Results: The cytologic findings showed diffuse or collective Tzanck cells in 3 of the 15 cases. The findings of the other 12 cases were nonspecific inflammatory changes compared to the control. The definitive diagnosis for each case was made according to histopathologic and direct immunofluorescence (DIF) findings. The 3 cases in which Tzanck cells were recognized in the cytologic smear were subsequently diagnosed as pemphigus vulgaris. The cases in which only nonspecific cytologic findings were obtained were later diagnosed by biopsy and DIF as mucous membrane pemphigoid or lichen planus. Conclusion: All the cytologic findings of the 15 patients, except for 3 cases in which Tzanck cells were found, were nondiagnostic. Therefore, the use of exfoliative cytology does not appear to be appropriate as a diagnostic tool for patients showing the clinical symptoms of desquamative gingivitis, because this technique adds to the cost and delays the definitive diagnosis. However, using the cytologic technique may occasionally be of some value as a minimally invasive screening tool when pemphigus vulgaris is suspected. Keywords: desquamative gingivitis, diagnosis, exfoliative cytology, lichen planus, mucous membrane pemphigoid, pemphigus vulgaris