Oral exfoliative cytology, while an economical and practical tool for diagnosis of squamous cell carcinoma and potentially malignant lesions, is not extensively used. The results of conventional (n = 89) and liquid-based (n = 411) oral diagnostic cytology cases are reported and compared to histological diagnosis. Cells were collected using either a Cytobrush device for conventional smears or a dermatological curette (AcuDispo) for liquid-based (Thin Prep) cytology. The "curette technique" allowed for the collection of "accidental" tissue fragments, utilized as microbiopsies. The sensitivity was 86.5% in conventional and 94.7% in liquid-based cytology; specificity was 94.3% and 98.9%, respectively; inadequate samples were present in 12.4% and 8.8% of cases, respectively. Although conventional cytology may be useful in oral squamous cell carcinoma and potentially malignant lesions, liquid-based cytology gives better results, enhances both the sensitivity and specificity, and also provides material for further investigations, e.g. DNA ploidy studies, microhistology, etc.