Narendra Modi, the man tipped to be India's next PM, has voted in his home state of Gujarat in the seventh phase of the general election.
He cast his vote at a school in the city of Ahmedabad. All 26 seats are up for grabs in the state.
Transport hubs in the city are bursting with people returning to their homes to vote, says the BBC's Sanjoy Majumder.
Andhra Pradesh also goes to the polls on Wednesday for the last time as a united state before it is divided.
It is among nine states and union territories sending 139 million eligible voters to make their choice between some 1,300 candidates contesting 89 seats on Wednesday.
India's general election, with 814 million eligible voters, is the world's biggest exercise in democracy and the governing Congress party is battling the opposition Bharatiya Janata Party (BJP) for power.
But it is the BJP's Modi who is ahead in all the opinion polls.
Congress is talking of aligning with Third Front, shows that they have already accepted defeat: Modi http://t.co/ot7QugbBow— Firstpost (@firstpostin) April 30, 2014
Modi was greeted by frenzied crowds who lined the street and climbed the roofs of surrounding buildings as he arrived at the polling station in Ahmedabad, our correspondent reports.
"The Congress party has already conceded defeat... It is the end of the mother-son government," he said after voting, in a reference to the Congress party chief Sonia Gandhi and her son Rahul.
He waved to his supporters flashing victory signs as he left. The police had a difficult time keeping the surging crowd at bay as they tried to reach Modi.
Our correspondent says everyone in the city is talking about Modi, their chief minister for more than a decade, and the man they want to see lead India.
He is standing for election from two seats - in the Hindu holy city of Varanasi as well as from Vadodara in Gujarat. If he wins both seats, he will have to relinquish one.
Andhra Pradesh - where voting for state assemblies is also taking place - is a key battleground for the general election.
The 17 parliamentary constituencies going to the polls on Wednesday will be part of the newly created state of Telangana next time round. Voting for the remaining 25 parliamentary seats which will constitute Andhra Pradesh after the state is split in two will be held on 7 May.
The main contest in the state is between the Congress party and the regional Telangana Rashtriya Samiti (TRS) - both are taking credit for the creation of Telangana and both are likely to benefit from the general belief that they helped set up the new state, BBC Hindi's Zubair Ahmed reports from Hyderabad.
"We will have jobs for our children. We will have uninterrupted supply of safe drinking water and electricity. We will have schools. The future of our children and grandchildren in the new state will be bright," Uttarapally Yadamma, a resident of an impoverished village near Hyderabad city, said.
Voting in phases
The marathon general election, which began on 7 April, will conclude on 12 May. Votes will be counted on 16 May.
The main contest is between the Congress, led by Rahul Gandhi, and Modi, the charismatic and controversial Hindu nationalist leader under whose watch Gujarat witnessed one of India's worst anti-Muslim riots in 2002. He has overseen impressive economic growth in the state which the BJP hopes will translate into votes nationwide.
Several smaller regional parties are also in the fray and if no single party wins a clear majority, they could play a crucial role in the formation of a government.
This includes the party of Arvind Kejriwal, at the helm of the anti-corruption Aam Aadmi (Common Man's) Party, which secured a spectacular result in Delhi local election last year.
Any party or coalition needs a minimum of 272 MPs to form a government.