An estimated 22 per cent of the 4.16 crore voters in Tamil Nadu exercised their franchise till noon with no untoward incidents reported from anywhere.
Tamil Nadu Chief Minister M Karunanidhi, AIADMK supremo Jayalalithaa, Union Home Minister P Chidambaram, MDMK leader Vaiko and Tamil 'Superstar' Rajnikant were among the early voters.
Police said polling was by and large peaceful.
In neighbouring Puducherry, about 25 per cent of the 7.62 lakh voters exercised there franchise for the lone seat in the first four hours, official sources said.
Polling began for 39 Lok Sabha seats in Tamil Nadu and the lone seat in Puducherrry amid tight security.
About one-lakh security personnel, including paramilitary forces are keeping vigil over 52,000 polling stations in Tamil Nadu.
The electoral fortunes of 824 candidates including Union Ministers P Chidambaram and T R Baalu, MK Azhagiri, Madurai-based son of DMK President and Chief Minister M Karunanidhi,CPI state secretary D Pandian, BJP state president L Ganesan and MDMK chief Vaiko are being decided today.
Voters were seen lining up before some polling booths early in the morning itself.