Oral carcinogenesis is a stepwise accumulation of genetic damage over time. The older cancer diagnostic aids had less specificity, were time-consuming, and produced interobserver bias. Technological and therapeutic advances in the recent years have helped to diagnose and treat this disease at an early stage. Advances in molecular biology over the past decade have helped us to enhance our understanding of the complex interplay between genetic, transcriptional, and translational alterations in human cancers. This review provides a summary of all the diagnostic modalities that were used earlier and the newer more advanced techniques with merits and demerits of each technique described briefly.