Historically, the screening of patients for signs of oral cancer and precancerous lesions has relied upon the conventional oral examination. A variety of commercial diagnostic aids and adjunctive techniques are developed to potentially assist in the screening of healthy patients for evidence of occult cancerous change. This paper is reviewing the literature associated with current oral cancer screening aids such as spectroscopy, chemoiluminescence, exfoliative cytopathology, vital staining and saliva as a diagnostic tool. Despite the increased public awareness of oral cancer, no technique or technology to date has provided definitive evidence to suggest that it improves the sensitivity or specificity of oral cancer screening beyond clinical oral examination alone.