scalpel biopsy can be used since it is invasive and has potential morbidity. Critical diagnostic tools are devised for early detection of oral dysplasia and malignancy since they are practical, non-invasive and can be easily done in an out-patient set-up. Diagnostic tests are brush biopsy, toluidine blue staining, salivary proteomics, DNA analysis, biomarkers and spectroscopy. This review explains the diagnostic aids and their value in detecting oral squamous cell carcinoma and its premalignant lesions