Among the early voters were the Bharatiya Janata Party's (BJP) state unit president B.S. Yeddyurappa and his family at Shikaripura in the Shimoga parliamentary seat, and BJP candidate Umesh Jadav at Chincholi in the Gulbarga (SC) constituency.
Yeddyurappa's second son B.Y. Raghavendra is contesting from Shimoga for the third time against Madhu Bangarappa, son of late Congress Chief Minster S. Bangarappa.
Jadav is contesting against Congress leader Mallikarjun Kharge, who is in the fray for a hat trick in the Lok Sabha.
An estimated 2.43 crore citizens -- 1.23 crore men, 1.20 crore women -- and some 10 lakh first time voters in the 18-19 age group, are on the electoral rolls to exercise their franchise.
"Polling will be held till 6 p.m. in the 14 parliamentary seats across the erstwhile Bombay province and the Hyderabad-Karnataka region," added the official.
The constituencies are Chikkodi, Belgaum, Bagalkot, Bijapur (SC), Gulbarga (SC), Raichur (ST), Bidar, Koppal, Bellary (ST), Haveri, Dharwad, Uttara Kannada, Davanagere and Shimoga.
The state's chief electoral office has identified 5,605 polling stations as critical with additional police deployment to ensure peaceful polling and avoid any untoward incident.
In all 237 candidates, including 10 women, are in the fray, with 164 as Independents.
With the ruling Janata Dal-Secular (JD-S) and Congress fielding common candidates as part of their pre-poll alliance, the BJP nominees are locked in a straight contest with them after nearly three decades.
While the Congress is contesting Chikkodi, Belgaum, Bagalkot, Gulbarga (SC), Raichur (ST), Bidar, Koppal, Bellary (ST), Haveri, Dharwad and Davanagere seats, the JD-S Bijapur (SC), Shimoga and Uttara Kannada.
BJP's Union Minister Anant Kumar Hegde is in the fray from Uttar Kannada on the state's west coast against Anand Asnotikar of the Janata Dal-Secular.
In the Bellary (ST) seat, BJP's Devandrappa is facing outgoing Congress member V.S. Ugrappa who won the seat in the November 2018 by-election.
In Dharwad, outgoing BJP MP Prahlad Joshi is taking on Vinay Kulkarni of the Congress. In Bidar, Congress state working President Eshwar Khandre is facing sitting BJP member Bhagawanth Khuba.
BJP's Union Minister Ramesh Jigajinagi is contesting against JD-S candidate woman leader Sunita Devanand.
The Congress has also fielded woman candidate Veena Kasappanavar in Bagalkot against outgoing BJP MP P.C. Gaddigoudar.
The BJP has not fielded any woman in this phase. Its sitting member Shobha Karandlaje re-contested from Udupi-Chikamagalur in the April 18 polling.