The turn out of voters was good in Kadapa since morning and it was 36.23 per cent by 1200 hours, official sources said.
Meanwhile, the polling percentage in Pulivendula assembly constituency, was 34.66 per cent, they said.
Polling in the Kadapa Lok Sabha seat had been peaceful with no major incidents of violence being reported anywhere.
Congress MLA from Kamalapuram G Veerasiva Reddy was put under house arrest following a complaint by YSR Congress party of former MP Y S Jagan Mohan Reddy.
Polling began at 8 am today for the by-election to Kadapa Lok Sabha and Pulivendula Assembly constituencies, which falls under Kadapa Lok Sabha seat, amid tight security.
There are 13.29 lakh voters in Kadapa Lok Sabha constituency and 1.89 lakh in Pulivendula Assembly segment.
About 12,000 policemen have been deployed for the smooth conduct of the polling process. Among the over 1,500 polling stations in Kadapa, 584 have been identified as sensitive, 187 as hyper sensitive and 487 as troublesome.
Significantly, the polling is being webcast to ensure transparency.