Oral exfoliative cytology is a simple yet a powerful tool for early detection of potentially malignant disorders of the oral mucosa as well as for some viral and fungal infections that involves the use of inexpensive instruments. The proper role of oral cytology in cancer diagnosis and detection has been studied by many researchers. Analysis of recent investigations confirms that the smear technic gives excellent results although not a substitute for biopsy, is an accurate diagnostic adjunct for the early detection of oral cancer. The use of oral exfoliative cytology in clinical practice declined due to the subjective nature of its interpretation, because there may be only a small number of abnormal cells identifiable in a smear. The more recent application of quantitative techniques has refined the potential role of cytology, stimulating a reappraisal of its value in the diagnosis of oral cancer. These studies indicate that oral cytology may provide an important adjunct in the assessment of the patient with a potentially cancerous oral lesion.