Voting for the by-poll in Sankarankoil assembly constituency of Tamil Nadu's Tirunelveli district began amid tight security at 8am on Sunday.
Thirteen candidates, including six independents, are in the fray vying for votes from 206,087 voters (male 102,921, female 103,166).
There are 242 polling booths in the constituency and voting would close at 5pm.
The polling process will be webcasted and will be monitored by the chief electoral officer using ten monitors installed in the control room of his office.
It will be a five cornered contest with AIADMK, DMK, DMDK, the Bharatiya Janata Party (BJP) and MDMK being the major parties in the arena.
The by-poll is necessitated by the death of sitting member, AIADMK's C.Karuppasamy, in October 2011 due to ill health.
The AIADMK has fielded V Muthuselvi while DMK and DMDK have pitted J.Jawahar Suryakumar and K.Muthukumar respectively against her.
MDMK which boycotted the assembly polls last year has fielded T.Sadan Thirumalaikumar while the BJP's candidate is L Murugan.
Counting of votes will begin at 8am Wednesday, said the Election Commission.