It is generally believed that Buddhism came to South India in the thrid century BCE, during the time of Emperor Ashoka or little earlier. However, the prevelence of Buddhism in the Tamil region till 3rd-4th centuries CE is not attested by any material evidence. The reason may be that consistent with the pan-Indian usage, perishable materials like wood and brick had been used for the construction of secular as well as religious edifices of the earlier times. However, the discovery of a large number of stone sculptures and bronze images datable to 5th-6th centuries CE and onwards at various places all over Tanil Nadu indicate the wide prevalence of Buddhism in the area. A few stone and bronze images and some of the inscriptions indicate that Buddhism existed in certain pockets in Tamil Nadu till 16th-17th centuries CE. Notwithstanding the few books and articles which have been published on Tamil Nadu Buddhism, a majority of them hardly give an authentic detail in a comprehensive manner on this theme. Moreover, in some of the publications, there is much haziness in identificaiton of Buddhist sites and a few Jaina sculptures and even the icons of Hindu gods and saints have also been included in the list erroneously. The author has meticulously re-examined almost all the Buddhist vestiges in Tamil Nadu and his work on this systematic survey and scrutiny of the Buddhist sites.